• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.7
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• pp.783-789
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• 2008

This experimental study describes the noise reduction and the feasibility of short current of a silencer for a high voltage COS(cut out switch) fuse of a transformer. When a high voltage COS fuse becomes a short circuit by the over current, the strong impulse noise over 150 dB(A) is generated. For the purpose of the reduction of impulse noise, in this study, the diffuser type and the reactive type silencers have been designed and tested, respectively. And also the electrical test on the short current is performed. From the experimental results, the well designed reactive type silencer has been shown to have the noise reduction of about 20 dB(A). It has been found that the feasibility of short current for the COS fuse is closely related to the porosity of the silencer.

• Journal of Korea Society of Digital Industry and Information Management
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• v.14 no.3
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• pp.29-38
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• 2018

It is the approach of embedded system design that analyzes COS(Cut Out Switch) failure in the power distribution and an instantaneous breakdown of power distribution supply could cause the weakness of industrial competence and therefore we need to feed the stable power distribution with developing the technology of open-source embedded system. In this paper, we apply the LoRa technology which is the Internet of Things(IoT) protocol for low data rate, low power, low cost and long range sensor applications. We designed the hardware and software architecture setup and experimented the embedded system with network architecture and COS monitoring system including accelerometer for detecting the failure of distribution line and sensing the failure of its fuse holder by recognizing the variation and collision and afterwards sending the information to a gateway. With experimenting we designed the embedded platform for sensing the variation and collision according to the COS failure, monitoring its fuse holder status and transferring the information of states with LoRa technology.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.71-74
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• 2005

This experimental study describes the propagation characteristics and reduction of impulse noises emitted from a high voltage COS(Cut Out Switch) fuse of a transformer. When a high voltage COS fuse becomes a short circuit by the over current. The peak sound Pressure above 150dB(A) is generated. In this study, an impulse noise generator is designed for generating the impulse noises similar to the noise level of COS fuse, which is utilized to test the noise reduction of a reactive silencer. The reactive silencers have been tested for 10 different types with each different porosity, hole diameter and length. From the experimental results, it is found that the reactive silencer has an excellent performance to greatly suppress the impulse noise and that its performance is closely connected with the porosity and hole diameter.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.483-491
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• 2014

In this study, we developed an M-COS (molit coagulant-dosing optimization system), which enables to apply the optimum coagulant dose determined in real time, in order to satisfy the total phosphorus (TP) regulation (0.5 mg/L), and then tested its field applicability. Field tests were conducted at three different periods in 2014 in a pilot plant where the M-COS was installed. Coagulant reduction rate by the M-COS was 10.4%, 15.3%, and 9.0% for each period (average 11.6%), when comparing with a control where coagulants were applied at a constant rate. Total cost for the M-COS or control was estimated by summing up the coagulant cost and sludge treatment cost, and then the resulting cost increase was predicted. Cost reduction rate by the M-COS was 13.8%, 20.0%, and 11.4% for each period (average 15.0%). This study indicates that the M-COS can be an alternative to a conventional system for TP treatment, with a better cost efficiency.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.86-96
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• 2015

According to previous research, the reason why Design-Build(hereinafter "DB") outperforms Design-Bid-Build(hereinafter "DBB") in terms of cost is due to less change orders(hereinafter "COs"). However, if biddropping was low for DBB resulting into increasing COs, then it would be wrong to conclude that DB is superior due to less COs. Therefore, in order to confirm such misjudgment, the attempt to comprehensively analyze biddropping, COs and delivery method was made as previous methods had analyzed either the relationship between delivery method and COs, or biddropping and COs. This research uses path analysis, which simultaneously compares effect sizes on COs according to delivery method and biddropping based on the project type, and validated the mediator effect. The research proved that DB outperforms DBB due to less COs cannot be validated as biddropping caused a mediator effect by intervening between the delivery method and COs for specific project types. Therefore, the mechanism of delivery method acts on COs through biddropping was established. Also, the identity of biddropping was investigated in a different perspective from previous research. Based on this result, this research is expected to help determine a delivery method by considering the mediator effect of specific projects and evaluate performance.

• Korean Journal of Microbiology
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• v.32 no.3
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• pp.198-201
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• 1994

The nucleotide sequence of the cohesive end site (cos) of Lactobacillus casei phage J1 genome was determined. Comparison between the nucleotide sequences of the circular cos and the left end of the linear J1 DNA showed that the nicking sites of the terminase were as follows: 5'- GGTCGGCC$\downarrow$ -3' 3'- $\uparrow$CCAGCCGG -5' The cohesive single-stranded ends of J1 were found to be 3'-protruding and composed of 8 nucleotides. The mol% G + C of the cohesive ends was 87.5. The cos site shows dyad symmetry from -33 to + 25 bp if the 5' terminal nucleotide of the left end of the linear J1 DNA is numbered +1. No homology was found among the cos sites of phages reported so far.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.256-261
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• 2004

In order to detect chitooligosaccharides (COS) in soybean paste, tandem immunoaffinity chromatography and enzyme-linked immunosorbent assay (ELISA) were developed. Polyclonal anti-chitooligosaccharides mixture (CaSM) antibody specific to COSM was attached to Sepharose gel for initial sample cleanup and concentration of COS in soybean paste. COS was eluted and quantified by competitive direct ELISA (cdELISA). Average ELISA recoveries from the column using binding buffer spiked with COSM at levels of 0.5, 2.0, 5.0, and $10.0\mu$g/ml were 79.8, 72.0, 77.7, and 60.6%, respectively, with a mean recovery of 72.5%. Mean inter-well and inter-assay coefficients of variation (CV) were 7.7% and 10.3%, respectively. Average recoveries from soybean paste spiked with COSM at levels of 2, 6, 20, and $60\mu$g/g were 115, 91.7, 91, and 73.3%, respectively, with a mean recovery of 92.8%. Mean inter-well and inter-assay CV were 12.9% and 16%, respectively. The COS was detected from 24 out of 25 homemade Korean soybean paste samples at an average of $14.0\mu$g/g (n, 25; range, $0-51.2 \mu$g/g) and from 13 out of 14 commercially made soybean paste samples at an average of $4.1\mu$g/g(n, 14; range, $0-18.4\mu$g/g). The tandem immunoaffinity chromatography-cdELISA that was developed in this study showed that the level of COS eluted from homemade soybean paste was higher than that of the commercially made ones. In addition, the level of COS eluted from commercially available soybean paste in Korea was higher than that of the ones in Japan.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.1078-1094
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• 2021

This research investigated the physio-chemical and microbial quality characteristics of dry fermented sausage from selected Pediococcus strains: P. acidiliactici (PE1) and P. pentosaceus (PE2) as compared to commercial starter culture (COS) during fermentation and ripening. Treatments showed no substantial variation (p<0.05) in water activity (a_w) values across the study period. PE1 and PE2 treatments exhibited similar (p>0.05) pH values and presented remarkable (p<0.05) lower volatile basic nitrogen (VBN) and thiobarbituric acid reactive (TBARS) content than COS treatment throughout the ripening period. However, the pH values in COS batch were considerably lower than others. PE1 samples presented a significant highest (p<0.05) counts both in lactic acid bacteria (LAB) and total plate count (TPC) than COS and PE2 treatments at 7 days fermentation, and it resulted in a similar and higher TPC count as COS after the ripening period. After the ripening process, treatments are ordered based on LAB counts as follows: COS>PE1>PE2. All batches presented similar redness and yellowness attributes since the 7 days of fermentation and in lightness across the study period. Treatments were similar (p>0.05) in springiness and chewiness traits across the study period and in hardness characteristics in the ripened products. Cohesiveness was higher in PE1 and COS batches. No variation (p>0.05) in aroma and sourness sensory attributes of treatments. The color attribute was highest (p<0.05) in PE1 and PE2 treatments and PE1 had the highest overall acceptability. The overall outstanding merit exhibited by PE1 can be utilized in the commercial production of high-quality dry fermented sausage.

• Communications of the Korean Mathematical Society
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• v.34 no.1
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• pp.1-16
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• 2019

Let a, b, P, and Q be real numbers with $PQ{\neq}0$ and $(a,b){\neq}(0,0)$. The Horadam sequence $\{W_n\}$ is defined by $W_0=a$, $W_1=b$ and $W_n=PW_{n-1}+QW_{n-2}$ for $n{\geq}2$. Let the sequence $\{X_n\}$ be defined by $X_n=W_{n+1}+QW_{n-1}$. In this study, we obtain some new identities between the Horadam sequence $\{W_n\}$ and the sequence $\{X_n\}$. By the help of these identities, we show that Diophantine equations such as $$x^2-Pxy-y^2={\pm}(b^2-Pab-a^2)(P^2+4),\\x^2-Pxy+y^2=-(b^2-Pab+a^2)(P^2-4),\\x^2-(P^2+4)y^2={\pm}4(b^2-Pab-a^2),$$ and $$x^2-(P^2-4)y^2=4(b^2-Pab+a^2)$$ have infinitely many integer solutions x and y, where a, b, and P are integers. Lastly, we make an application of the sequences $\{W_n\}$ and $\{X_n\}$ to trigonometric functions and get some new angle addition formulas such as $${\sin}\;r{\theta}\;{\sin}(m+n+r){\theta}={\sin}(m+r){\theta}\;{\sin}(n+r){\theta}-{\sin}\;m{\theta}\;{\sin}\;n{\theta},\\{\cos}\;r{\theta}\;{\cos}(m+n+r){\theta}={\cos}(m+r){\theta}\;{\cos}(n+r){\theta}-{\sin}\;m{\theta}\;{\sin}\;n{\theta},$$ and $${\cos}\;r{\theta}\;{\sin}(m+n){\theta}={\cos}(n+r){\theta}\;{\sin}\;m{\theta}+{\cos}(m-r){\theta}\;{\sin}\;n{\theta}$$.

• Journal of Life Science
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• v.13 no.3
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• pp.324-332
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• 2003

The objective of this study was to examine if transient transfection of CAR can transactivate CYP2B1 PBRU reporter gene in COS cells in which the endogenous CYP2B1 gene is not induced by PB. In non-transfeced cells of both Hep G2 and COS, the endogeneous expression of CAR was not detected by antibody against CAR. When cultured cells were transfected with CAR expression plasmid, mCAR1-GFP, both cell types expressed high levels of CAR protein and could allow to examine the effect of CAR in PBRU transactivation. Both cell types expressed endogenous RXR and transfection of RXR expression plasmid dramatically increased its protein expression. Whereas CAR transactivated PBRU2C1Luciferase about 12 fold as compared to 2C1Luciferase in Hep G2 cells, it did not stimulate the luciferase activity of the PBRU reporter gene in COS cells. These results indicate that Hep G2 cells can respond to CAR differently from COS cells, and suggest that factors other than CAR and RXR may be required in inducing PBRU activation and the expression of these factors may be different between liver and kidney.