• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.377-389
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• 2018

In this study, a novel microalgal strain, Desmodesmus sp. KAERI-NJ5, was isolated, identified, and evaluated as a candidate for biodiesel feedstock. In a preliminary study, the effects of four general microalgal growth factors, including temperature, pH, light intensity, and concentration of nitrogen source ($KNO_3$), on the microalgal photoautotrophic growth were evaluated. With the exception of light intensity, the growth factors needed to be optimized for the microalgal biomass production. Optimization was done using response surface methodology. The optimal conditions for biomass production were pH 6.54, $27.66^{\circ}C$, and 0.52 g/l $KNO_3$. The biomass production at the optimal conditions was 1.55 g/l, which correlated well with the predicted value of 1.5 g/l. The total lipid and fatty acid methyl ester contents of the cells grown at the optimal conditions were 49% and 21.2% of cell dry weight, respectively. To increase the lipid content of the biomass, microalgae were challenged by nitrogen starvation. Enhancement of total lipid and fatty acid content up to 52.02% and 49%, respectively, were observed. Lipid analysis of the nitrogen-starved cells revealed that C16 and C18 species accounted for 95.9% of the total fatty acids. Among them, palmitic acid (46.17%) and oleic acid (39.43%) dominantly constituted the algal fatty acids. These results suggest Desmodesmus sp. KAERI-NJ5 as a promising feedstock for biodiesel production.

• The Journal of the Acoustical Society of Korea
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• v.12 no.1
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• pp.47-54
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• 1993

Performance analysis is very important to transmit the high quality information and to construct the optimal system for the minimze the noise from the channel of spread spectrum system. In this paper the error rate performance is analyzed with computer simulation in noncoherent frequency hopping M-qry frequency shift keying(FH/MFSk) systems with regard to thermal noise under the partial band jamming environments. AS a result, in case the thermal noise is disregarded, bit error probability of system in jamming fraction ρ and Eb/Nj(bit energy to jamming power density) is reduced with the increase of K and in worst case 32FSK system is better than 2FSK system by 3.23dB with the variatio of Eb/Nj. In case thermal noise is considered, bit error probability of system by 3.23dB with the variation of Eb/Nj. In case thermal noise is considered, bit error probability of system are reduced with the increase of K and Eb/No(bit energy to thermal noise density). Bit error probability in connection with worst case ρ is not largely influenced form over the 14dB to K=1 and 8dB to K=5 accordingly thermal noise disregarding. These results may be useful for avoiding the common vulnerabilities when the spread spectrum system is designed.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.136-142
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• 2008

We conducted this study to compare physiological response according to growing conditions between superior and inferior family of Pinus densiflora. In 1981, open-pollinated (OP) progenies of P. densiflora were planted in Chuncheon (CC) and Naju (NJ). We selected KW2 as a superior family and KW23 as a inferior family based on volume index among 30 OP progenies. We calculated general combining ability of each 30 OP progenies in each sites, and compared family growth rank. We collected needles of selected families in CC and NJ, and analyzed chlorophyll content, nitrated reductase (NR) activity, nitrogen content, and superoxide dismutase (SOD) acitivity. In CC, chlorophyll content and nitrogen content were more in needles of KW2 than those of KW23. In NJ, KW2 showed higher NR activity than KW23, and according to site, families in CC showed higher NR activity than those in NJ. SOD activities of both families were higher in NJ, and KW23 showed higher activity than KW2 in both sites. Consequently, inconsistency of the growth performance of two families was caused by different genetic and physiological responses.

• Water for future
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• v.25 no.4
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• pp.31-36
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• 1992

• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.255-262
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• 2016

The carrageenan-degrading marine bacterium Vibrio sp. strain NJ-2 was isolated from rotten red algae, and κ-carrageenase with high activity was purified from the culture supernatant. The purified enzyme with molecular mass of 33 kDa showed the maximal activity of 937 U/mg at 40℃ and pH 8.0. It maintained 80% of total activity below 40℃ and between pH 6.0 and 10.0. The kinetics experiment showed the K_m and V_max values were 2.54 g/ml and 138.89 mmol/min/mg, respectively. The thin layer chromatography and ESI-MS analysis of hydrolysates indicated that the enzyme can endolytically depolymerize the κ-carrageenan into oligosaccharides with degrees of depolymerization of 2-8. Owing to its high activity, it could be a valuable tool to produce κ-carrageenan oligosaccharides with various biological activities.

• Journal of Communications and Networks
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• v.3 no.4
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• pp.383-395
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• 2001

Recent measurement and simulation studies have revealed that wide area network traffic displays complex statistical characteristics-possibly multifractal scaling-on fine timescales, in addition to the well-known properly of self-similar scaling on coarser timescales. In this paper we investigate the performance and network engineering significance of these fine timescale features using measured TCP anti MPEG2 video traces, queueing simulations and analytical arguments. We demonstrate that the fine timescale features can affect performance substantially at low and intermediate utilizations, while the longer timescale self-similarity is important at intermediate and high utilizations. We relate the fine timescale structure in the measured TCP traces to flow controls, and show that UDP traffic-which is not flow controlled-lacks such fine timescale structure. Likewise we relate the fine timescale structure in video MPEG2 traces to sub-frame encoding. We show that it is possibly to construct a relatively parsimonious multi-fractal cascade model of fine timescale features that matches the queueing performance of both the TCP and video traces. We outline an analytical method ta estimate performance for traffic that is self-similar on coarse timescales and multi-fractal on fine timescales, and show that the engineering problem of setting safe operating points for planning or admission controls can be significantly influenced by fine timescale fluctuations in network traffic. The work reported here can be used to model the relevant characteristics of wide area traffic across a full range of engineering timescales, and can be the basis of more accurate network performance analysis and engineering.

• The Journal of Korean Obstetrics and Gynecology
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• v.31 no.1
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• pp.122-137
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• 2018

Objectives: This study is to review the effect of Korean medicinal herbs on treatment of polycystic ovary induced rat models reported in domestic & foreign journals. Methods: 7 electronic databases (Pubmed, CNKI, EMBASE, Oasis, RISS, CENTRAL, Koreankt) were searched with term as polycystic ovary, and study reports on polycystic ovary impairment with Korean medicinal herbs. After selecting several studies, the analysis was focused on items reflected in the Rotterdam criteria for diagnosis of polycystic ovary syndrome such as hyperandrogenism (HA), ovarian weight, the number of follicle cysts, estrous cycles, and etc. Results: 15 studies were reviewed. As a polycystic ovary induction material, estradiol valerate (EV) was used in 9 studies, testosterone propionate (TP) in 2 studies and dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA), Poretsky's method and letrozole (LE) was used in rest 4 studies, respectively. Tribulus terrestris (TT), Nardostachys jatamansi (NJ), Lycii cortex (LC), Cinnamomum cassia kees (CCK) and Atractylodis macrocephalae koidz (AMK) produced statistically significant results related to hyperandrogenism. In ovarian weight, Silybum marianum (SM), AMK and Alllium sativum (AS) were statistically significant. In the the number of follicle cysts, SM and TT were statistically significant. In estrous cycles, AMK, NJ, TT and Coix lacryma-jobi (CL) were statistically significant. Conclusions: Based on the diagnosis criteria of Rotterdam, TT, NJ, AMK, SM, AS, and CL produced statistically significant results in rat model.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.161-165
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• 1997

The R-mb locus of maize is one of several genes that encode tissue-specific transcriptional regulator for the anthocyanin biosynthesis in plant parts and the aleurone layer in seeds. We found that the seed pigment frequencies gradually decreased at selfed progenies of the R-mb genetic stocks. In order to analyze the genomic structure of R-mb locus components, genomic Southern blot was performed by using R specific probe, pR-nj:1. Two bands were detected at the size of about 3.9 and 7.75kb. Five R-mb positive clones (mb-II, III, V,Ⅵ, and Ⅶ) were obtained by screening of maize genomic λFIXII library using R specific probe pR-nj:1. We constructed the restriction map of clone mb-II (7.75Kb positive) and mb-Ⅵ (3.9Kb positive), and have compared these with other R locus genes. From genetic and molecular analysis, it is suggested that R-mb complex consists two copy of R elements, and each element shows the paramutagenic and gene silencing effects by the fashion of cis-inactivation.

• Journal of Life Science
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• v.24 no.6
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• pp.626-632
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• 2014

The genetic structure and phylogenetic relationship were investigated in Korean red spotted grouper populations using the nucleotide sequence polymorphisms of the mitochondrial DNA (mtDNA) cytochrome c oxidase subunit I (COI) gene. The COI gene was sequenced showed 99.1-99.8% identity with the EF607565 sequence previously reported. A total of twenty haplotypes were found, and the Korean population showed nineteen haplotypes. Among those, Hap_03 and Hap_08 showed Jeju-do and China-specific COI sequences, respectively. However, Hap_07 had twelve COI sequences from South Korea and records from Hong Kong and Taiwan. Neighbor-joining (NJ) trees constructed from the phylogenetic analyses based on the polymorphisms of the COI haplotypes showed a monophyletic branching pattern within the genus Epinephelus. This indicated that the red spotted grouper populations had evolved from common maternal ancestors. In addition, the Hap_08, which had the COI sequence recorded only from China Sea, was found in the middle of the NJ tree nearby Hap_07 and showed a close relationship with Hap_07. This indicates that Chinese red spotted grouper is also maternally related to other populations in East Asia. Consequently, East Asian red spotted grouper populations are maternally related, as well as sharing the same evolutionary history, and are still affected by the East Asian ocean current (Kuroshio). These findings help to explain the genetic structure and phylogenetic relationship of red spotted grouper and also contribute to research on artificial breeding and industrialization.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.6
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• pp.789-793
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• 2008

The gayal (Bos frontalis) in China is a very rare semi-wild and semi-domestic bovine species. There still exist remarkable divergences on the gayal's origin and taxonomic status. In the present study, the cytochrome b (Cyt b) gene entire sequences (1,140 bp) of 11 gayals in Yunnan China were analyzed. Combined with other bovine Cyt b sequences cited in GenBank, the phylogenetic trees of genus Bos were reconstructed by neighbor-joining (NJ) and maximum parsimony (MP) methods with Bubalus bubalis as outgroup. Sequence analysis showed that, among 1,140 sites compared for 11 gayals, 95 variable sites (8.33% of all sites) and 6 different haplotypes were observed, showing abundant mitochondrial genetic diversity in gayals. Both NJ and MP trees demonstrated that gayals in this study were markedly divided into three embranchments: one embranchment clustering with Bos gaurus, another clustering with Bos taurus, and the third clustering with Bos indicus. The result of phylogenetic analysis suggested that the gayal might be the domesticated form of the gaur, and a great proportion of the gayal bloodline in China was invaded by other bovine species.