• Journal of the Korean Mathematical Society
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• v.56 no.2
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• pp.539-558
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• 2019

An ideal of a commutative ring is called a d-ideal if it contains the annihilator of the annihilator of each of its elements. Denote by DId(A) the lattice of d-ideals of a ring A. We prove that, as in the case of f-rings, DId(A) is an algebraic frame. Call a ring homomorphism "compatible" if it maps equally annihilated elements in its domain to equally annihilated elements in the codomain. Denote by $SdRng_c$ the category whose objects are rings in which the sum of two d-ideals is a d-ideal, and whose morphisms are compatible ring homomorphisms. We show that $DId:\;SdRng_c{\rightarrow}CohFrm$ is a functor (CohFrm is the category of coherent frames with coherent maps), and we construct a natural transformation $RId{\rightarrow}DId$, in a most natural way, where RId is the functor that sends a ring to its frame of radical ideals. We prove that a ring A is a Baer ring if and only if it belongs to the category $SdRng_c$ and DId(A) is isomorphic to the frame of ideals of the Boolean algebra of idempotents of A. We end by showing that the category $SdRng_c$ has finite products.

• Journal of Microbiology and Biotechnology
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• v.34 no.8
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• pp.1636-1641
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• 2024

A Gram-stain-positive, aerobic, white-coloured, rod-shaped bacteria, designated as a strain dW9^T, was isolated from soil. Strain dW9^T was catalase-positive and oxidase-negative. Strain dW9^T grew at temperature of 20-37℃ and at pH of 5.0-7.0. Phylogenetic and 16S rRNA gene analysis indicated that strain dW9^T belonged to the genus Paenibacillus with its closest relative being Paenibacillus filicis S4^T (97.4% sequence similarity). The genome size of dW9^T was 7,787,916 bp with DNA G+C G+C content of 51.3%. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values of dW9^T with its closest relatives were found to be <22.0% and <74.0%, respectively. The only respiratory quinone was MK-7, and the major fatty acids were antiso-C_15:0 and iso-C_16:0. Overall, the comprehensive taxonomic analysis revealed that strain dW9^T met all the fundamental criteria to be classified as a novel species within the genus Paenibacillus. Accordingly, we propose the name Paenibacillus gyeongsangnamensis sp. nov., with the type strain dW9^T (=KCTC 43431^T =NBRC 116022^T).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.9
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• pp.1039-1046
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• 2007

In this paper, a coupled-defected ground structure(C-DGS) using negative inductive coupling is proposed and a bandstop filter(BSF) using C-DGS is designed and fabricated. The proposed C-DGS is the closely-located DGS cells for the negative coupling, the negative coupling of ground currents between adjacent DGS cells greatly improves the stopband characteristics. The proposed BSF utilizing the sharp cutoff response of the C-DGS has a -10 dB rejection band from 4 GHz to 11.3 GHz. A maximum attenuation rate is -64.3 dB/GHz in 3 cell structure, -108 dB/GHz in 5 cell structure. The C-DGS BSF shows the improved attenuation rate 3.8 times in 3 cell structure, 2.4 times in 5 cell structure, Also, the C-DGS BSF is reduced to 35.2 % and 40 % of the DGS BSF, respectively, due to the closely-located DGS cells. We fabricated the single gate mixer using C-DGS BSF. The single gate mixer has 6.6 dB conversion gain.

• Journal of Korean Medicine Rehabilitation
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• v.34 no.2
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• pp.15-28
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• 2024

Objectives We used the D-galactose (D-gal) induced C2C12 myoblast senescence model to investigate whether ethanol extract of Perilla. fructescens leaves (EEPF) could delay cellular senescence and regulate related mechanisms. Methods C2C12 myogenic cells were cultured in an incubator under 37 ℃ and 5% CO₂ conditions. EEPF, dried perilla leaves were pulverized and extracted at 1:10 (v/v) at 50 ℃ for 4 hours. Cell counting kit-8 and western blot analysis was performed. Annexin V-FITC apoptosis detection kit and DAPI staining was applied. Catalase (CAT), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), superoxide dismutase (SOD), and malondialdehyde analysis kits were used. To measure the level of reactive oxygen species generation, staining and flow cytometry was used. To analyze the mitochondrial activity, membrane potential changes were measured using JC-1. 𝛽-gal activity was analyzed using SA-𝛽-gal staining solution, and DNA damage was analyzed by using 𝛾-H2AX. Quantikine ELISA kit was used to analyze inflammatory cytokine production. Results According to the results of this study, EEPF significantly alleviated the decrease in cell viability in C2C12 cells treated with D-gal and suppressed the decrease in the expression of proliferating cell nuclear antigen. EEPF also markedly blocked D-gal-induced C2C12 cell apoptosis and restored reduced activity of CAT, GSH-Px, T-AOC, SOD. In addition, EEPF suppressed the decrease in 𝛽-galactosidase activity, the induction of DNA damage and the increase in expression of senescence-associated secretory phenotype proteins such as p16, p53 and p21 in D-gal-treated C2C12 cells. Furthermore, EEPF significantly attenuated D-gal-induced production and expression of inflammatory cytokines such as interleukin (IL)-6 and IL-18. Conclusions The results of this study indicate that EEPF can be used as a potential candidate for the prevention and treatment of muscle aging.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.49-56
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• 2009

The objective was to determine the effects of supplementation of protected conjugated linoleic acid (CLA), CLA-20 comprising 10% each of cis-9, trans-11 and trans-10, cis-12, on milk production and fatty acid profiles in plasma and milk in lactating dairy cows. Five mid-lactation, multiparous crossbred Holstein Friesian cows with average 402${\pm}$20 kg BW were used in a 5${\times}$5 Latin square design for 21-d periods. Cows were given a total mixed ration (TMR) and supplemented with CLA-20 at 0, 20, 40, 80 and 160 g/d. The results showed that dry matter intake depression occurred in cows supplemented with CLA-20 at 160 g/d. Milk production slightly increased when CLA-20 supplementation was at 20, 40 and 80 g/d. However, 3.5% fat-corrected milk (FCM) was not affected by CLA-20 supplementation. Increased levels of CLA-20 supplementation resulted in a significantly decreased percentage of milk fat. Plasma concentrations of fatty acid were not altered by the amounts of CLA-20 supplementation except for the concentration of trans-10, cis-12 CLA. For all dietary treatments, percentages of fatty acids (C4:0, C6:0, C8:0, C13:0, C14:0 C14:1 C15:0 C15:1 C16:0, C16:1, C18:1n9t, C18:2n6t, C18:2n6c, C20:0, C18:3n6, C18:3n3, C20:1 and C20:3n6) in milk fat were similar. Concentrations of C10:0, C11:0, C12:0 and C18:1n9c were decreased cubically and C18:0 was elevated linearly (p<0.01) according to the increased amounts of CLA-20 supplemented. The linear increase was observed for cis-9, trans-11 CLA (0.62, 1.17, 1.94, 1.87 and 1.82% of total fatty acid), trans-10, cis-12 CLA (0.01, 0.63, 0.67, 0.93 and 0.95% of total fatty acid) and total CLA (0.80, 2.25, 3.16, 3.97 and 3.94% of total fatty acid) in milk fat from 0 to 160 g/d of CLA-20 supplement. In conclusion, concentration of cis-9, trans-11 CLA in milk fat was concomitantly elevated at an increasing rate with the increased amounts of CLA-20. Based on the results in this study, supplementation of CLA-20 at 80 g/d optimally enhanced total CLA in milk fat.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8140-8146
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• 2015

The objective of this study is to experimentally investigate the cooling performance characteristics with the consideration of the temperature variations of the enclosure of the 400W ferrofluid active speaker having both woofer and amplifier heat sinks. In order to do this, the heat sinks for both woofer and amplifier was designed ant applied to 400W ferrofluid active speaker. As a result, the cooling performance of the developed 400W ferrofluid active speaker was improved and the temperature of the enclosure after 120 min at steady state increased by $2.8^{\circ}C$ with the increase of the outdoor temperatures from $25^{\circ}C$ to $29^{\circ}C$. In addition, the overall sound pressure level of the developed 400W ferrofluid active speaker showed 111.8 dB and improved 1.9 dB higher than 109.9 dB of the existed speaker.

• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.152-157
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• 1998

To analyze the role of the C and D domains in the cyclization activity of cyclodextrin glucanotransferase (CGTase), two plasmids, pKB1ΔC300 and pKB1ΔD96, were constructed in which DNA regions encoding 100 and 32 amino acids, respectively, from the C and D domains of B. stearothermophilus NO2 CGTase were deleted. The mutated CGTase from the pKBlΔC300 produced much lower amounts of ${\alpha}$-, ${\beta}$-, and $\gamma$-cyclodextrin (CD) than the parental CGTase. However, the mutated CGTase from the pKBlΔD96 showed a similar production pattern of CDs to wild-type CGTase. The production ratios of the ${\alpha}$-, ${\beta}$- and $\gamma$-CDs were not affected by the deletions, when compared to those of parental CGTase. The optimum temperature of the mutated CGTase from the pKBlΔC300 was decreased from $60^{\circ}C$ to $55^{\circ}C$. The optimum pH of the mutated CGTase from the pKB1D96 was shifted from 6.0 to 7.0. The thermostability of the two mutant CGTases were not changed. From these results, it is suggested that the C and D domains are not related to cyclization activity directly because mutant-enzymes deleted C or D domains still possessed their activity. However, they are important for other enzymatic properties such as productivity and pH optimum as a partition of CGTase tertiary structure.

• Journal of Microbiology and Biotechnology
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• v.24 no.6
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• pp.795-802
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• 2014

The aim of this study was to determine the effects of temperature and supplementation with skim milk powder (SMP) on the microbial and proteolytic properties during the storage of cottage cheese. Cottage cheese was manufactured using skim milk with 2% SMP and without SMP as the control, and then stored at $5^{\circ}C$ or $12^{\circ}C$ during 28 days. The chemical composition of the cottage cheese and the survival of the cheese microbiota containing starter lactic acid bacteria (SLAB) and non-starter culture lactic acid bacteria (NSLAB) were evaluated. In addition, changes in the concentration of lactose and lactic acid were analyzed, and proteolysis was evaluated through the measurement of acid soluble nitrogen (ASN) and non-protein nitrogen (NPN), as well as electrophoresis profile analysis. The counts of SLAB and NSLAB increased through the addition of SMP and with a higher storage temperature ($12^{\circ}C$), which coincided with the results of the lactose decrease and lactic acid production. Collaborating with these microbial changes, of the end of storage for 28 days, the level of ASN in samples at $12^{\circ}C$ was higher than those at $5^{\circ}C$. The NPN content was also progressively increased in all samples stored at $12^{\circ}C$. Taken together, the rate of SLAB and NSLAB proliferation during storage at $12^{\circ}C$ was higher than at $5^{\circ}C$, and consequently it led to increased proteolysis in the cottage cheese during storage. However, it was relatively less affected by SMP fortification. These findings indicated that the storage temperature is the important factor for the quality of commercial cottage cheese.

• JSTS:Journal of Semiconductor Technology and Science
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• v.5 no.2
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• pp.89-101
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• 2005

Research on highly abstracted system modeling and simulation has received a great deal of attention as of the concept of platform based design is becoming ubiquitous. From a practical design point of view, such modeling and simulation must consider the following: (i) fast simulation speed and cycle accuracy, (ii) early availability for early stage software development, (iii) inter-operability with external tools for software development, and (iv) reusability of the models. Unfortunately, however, all of the previous works only partially addresses the requirements, due to the inherent conflicts among the requirements. The objective of this study is to develop a new system design methodology to effectively address the requirements mentioned above. We propose a new transaction-level system modeling methodology, called ViP (Virtual Platform). We propose a two-step approach in the ViP method. In phase 1, we create a ViP for early stage software development (before RTL freeze). The ViP created in this step provides high speed simulation, lower cycle accuracy with only minor modeling effort.(satisfying (ii)). In phase 2, we refine the ViP to increase the cycle accuracy for system performance analysis and software optimization (satisfying (i)). We also propose a systematic ViP modeling flow and unified interface scheme based on utilities developed for maximizing reusability and productivity (satisfying (ii) and (iv)) and finally, we demonstrate VChannel, a generic scheme to provide a connection between the ViP and the host-resident application software (satisfying (iii)). ViP had been applied to several System-on-a-chip (SoC) designs including mobile applications, enabling engineers to improve performance while reducing the software development time by 30% compared to traditional methods.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.232-236
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• 1992

In order to manufacture of soy paste, Changes of chemical composition and enzyme activity of soybean by different processing method were investigated. The results are summarized as follows: Changes of chemical compositions were; Raw(A) and soaked(B) soybeans contain about 2% of more crude fat than roasted(C) and steamed(D) soybeans, roasted and steamed soybeans contain $1.16{\sim}1.74%$ of more protein than those of raw and soaked soybeans, and Raw and roasted soybeans contain $0.11{\sim}0.41%$ of more crude fiber than those of soaked and steamed soybeans. ${\alpha}-amylase$, ${\beta}-amylase$, protease, lipase activity of raw and soaked soybeans were $2{\sim}5$ folds higher than those of roasted and steamed soybeans. Trypsin inhibitor activity of raw, soaked, roasted and steamed soybeans was indicated 56.7%, 42.9%, 32.9% and 20.8% in the order, respectively.