• Current Photovoltaic Research
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• v.2 no.4
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• pp.182-188
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• 2014

For the dissemination of new and renewable energy, Korean government introduced a renewable portfolio standard (RPS) scheme in 2012 after terminating feed-in tariff (FIT) scheme that was introduced in 2004. With the RPS scheme, 64.7% of its own goal (95.7% in PV and 63.3% in non-PV) was achieved in 2012 and 67.2% of that (94.9% in PV, 65% in non-PV) was achieved in 2013. The deployment of PV systems met the goal very well and that of non-PV did not. Recently, Korean government revised the target year of supplying 10% electricity from new and renewable energy from 2022 to 2024 and released a couple of measures on PV area. Recent studies showed that the bankability of a project plays a key role for PV dissemination. Therefore, the dissemination should be assessed from the point of bankability under the RPS scheme and a little adjustment is necessary to achieve the goal. Especially, installing a small size PV (<100 kwp) system needs a minimum REC price or a FIT scheme. In non-PV area, permission process is a common bottleneck and the related regulation should be eased. In addition, to achieve the long term goal, an implementing scenario has to be prepared. Currently, the portion of the waste-gas energy originated from fossil fuel is too large among the new and renewable energy sources and the portion should be lowered or eliminated in the 10% of electricity supply goal. Seoul Metropolitan Government (SMG) has its own FIT scheme for PV dissemination from 2014 SMG and revised the PV tariff from 50 to 100 won/kwh in effective of 2015. It is worth to spread the other provinces.

• Wind and Structures
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• v.35 no.4
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• pp.269-285
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• 2022

The pressure-mitigating effects of a high-speed train passing through a tunnel with a partially reduced cross-section are investigated via the numerical approach. A compressible, three-dimensional RNG k-ε turbulence model and a hybrid mesh strategy are adopted to reproduce that event, which is validated by the moving model test. Three step-like tunnel forms and two additional transitions at the tunnel junction are proposed and their aerodynamic performance is compared and scrutinized with a constant cross-sectional tunnel as the benchmark. The results show that the tunnel step is unrelated to the pressure mitigation effects since the case of a double-step tunnel has no advantage in comparison to a single-step tunnel, but the excavated volume is an essential matter. The pressure peaks are reduced at different levels along with the increase of the excavated earth volume and the peaks are either fitted with power or logarithmic function relationships. In addition, the Arc and Oblique-transitions have very limited gaps, and their pressure curves are identical to each other, whereas the Rec-transition leads to relatively lower pressure peaks in C_Pmax, C_Pmin, and ΔC_P, with 5.2%, 4.0%, and 4.1% relieved compared with Oblique-transition. This study could provide guidance for the design of the novel railway tunnel.

• Journal of fish pathology
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• v.32 no.2
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• pp.69-80
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• 2019

We performed MLSA (multilocus sequence analysis) and phenotypic characterization of Aliivibrio species isolated from walleye pollock (Gadus chalcogrammus) maintained in 3 different facilities of Gangwon Province, the east coast of Korea. Of 38 Aliivibrio species identified by 16S rDNA sequences, 12 strains were randomly selected and MLSA was conducted with 5 house-keeping genes (gapA, gyrB, pyrH, recA and rpoA) and 16S rDNA gene. Phylogenetic analysis and homology of the concatenated sequences (4,580 bp) with other Vibrionaceae genera revealed that 4 strains (GNGc16.1, YYGc16.1, YYGc16.2, GSGc18.1) were identified as Aliivibrio logei and one strain (GSGc16.1) as A. wodanis. One strain (GSGc17.1) was tentatively identified as A. logei, but needs further analysis because it did not belong to the same clade with A. logei type strain. 6 strains (GSGc17.2, GNGc16.2, GSGc16.2, GSGc17.3, GSGc18.2, GSGc17.4) need further investigation as potential novel species. Either phenotypic characterization or 16S rDNA sequence alone did not provide enough information for identification of Aliivibrio strains at the species level. A. logei and A. wodanis are generally known as non-pathogenic bacteria, but also known as opportunistic or secondary pathogens of cold water fishes. Cares should be taken to prevent potential outbreaks due to these bacteria, although there was no outbreaks during the sampling period.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.12
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• pp.1059-1066
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• 2007

An experimental study has been conducted to investigate the flow separation control effects of a blowing jet on an elliptic airfoil at a Reynolds number of 7.84×105 based on the chord length. A blowing jet was obtained by pressing a plenum inside the airfoil and ejecting flow out of a thin jet slot that located in leading edge or trailing edge. The experimental results have shown that the blowing jet had an effect of suppressing the flow separation, resulting in the higher suction pressure distribution and higher normal force. The increase in Cn was more pronounced at higher incidence, whereas the effectiveness of the blowing jet reduced at lower incidences. The leading edge pulsating blowing with 90° was the most effective in controlling the flow separation than other types of blowing jet configuration tested in this research. Moreover, when the pulsating blowing was applied, the stall angle was postponed about 2°-3°. The continuous and pulsating blowing jet is a direct and effective flow separation control for improving the aerodynamic characteristics and performances of airfoil.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1968-1976
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• 2006

Recombinant E. coli ACV 1003 (recA:: lacZ) was used to measure low concentrations of DNA-damaging chemicals, which produce $\beta$-galactosidase via an SOS regulon system. Very low $\beta$-galactosidase activities of less than 0.01 unit/ml, $\beta$-galactosidase produced through an SOS response corresponding to the 10 ng/ml (ppb) of DNA damaging chemicals in the environment, can be rapidly determined by using an alternative interferometric biosensor with optically flat thin films of porous silicon rather than by the conventional time-consuming Miller's enzyme assay as well as the ELISA method. fu order to enhance the sensitivity in the interferometry, it needs to obtain more uniform distribution and higher biolinking efficiency, whereas interferometric sensing is rapid, cheap, and advantageous in high throughput by using a multiple-well-type chip. In this study, pore size adjusted to 60 nm for the target enzyme $\beta$-galactosidase to be bound on both walls of a Si pore and a calyx crown derivative was apllied as a more efficient biolinker. Furthermore, anti-$\beta$-galactosidase was previously functionalized with the biolinker for the target $\beta$-galactosidase to be specifically bound. When anti-$\beta$-galactosidase was bound to the calyx-crown derivative-linked surface, the effective optical thickness was found to be three times as high as that obtained without using anti-$\beta$-galactosidase. The resolution obtained was very similar to that afforded by the time-consuming ELISA method; however, the reproducibility was still unsatisfactory, below 1 unit $\beta$-galactosidase/ml, owing to the microscopic non-uniform distribution of the pores in the etched silicon surface.

• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.313-319
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• 2018

Halophilic lactic acid bacteria (LAB) were isolated from myeolchi-jeotgal (23% NaCl, w/v) fermented in jangdok (Korean earthenware) located outside a house. They were identified as Tetragenococcus halophilus by 16S rRNA and recA gene sequencing. Four T. halophilus isolates showing high protease activities were selected for further studies. Four strains grew well, reaching $OD_{600}$ values of 0.75-0.92 at 18% NaCl content (w/v) and 0.28-0.44 at 23% salt. They showed rapid growth, attaining $OD_{600}$ values of 1.1-1.2 at $20-30^{\circ}C$, but did not grow at $4^{\circ}C$. At $15^{\circ}C$, the highest $OD_{600}$ values, which exceeded 0.6, were observed at 20 days, and were higher than those of cultures at $37^{\circ}C$ and $42^{\circ}C$ (approximately 0.5). Four isolates grew best in broth where the initial pH was adjusted to 8 and did not grow at $pH{\leq}4$. T. halophilus BS2-36 showed the highest survival ratio of 18.7% after 2 hours of exposure at pH 3. BS2-36 showed the highest survival ratio (1.29%) in presence of 0.3% bile salts. T. halophilus BS2-36 seems a promising candidate as a starter for jeotgal and other fermented foods with high salinities.

• Journal of Microbiology
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• v.42 no.4
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• pp.255-266
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• 2004

Papillomaviruses infect a wide variety of animals, including humans. The human papillomavirus (HPV), in particular, is one of the most common causes of sexually transmitted disease. More than 200 types of HPV have been identified by DNA sequence data, and 85 HPV genotypes have been well char­acterized to date. HPV can infect the basal epithelial cells of the skin or inner tissue linings, and are, accordingly, categorized as either cutaneous or mucosal type. HPV is associated with a panoply of clin­ical conditions, ranging from innocuous lesions to cervical cancer. In the early 1980s, studies first reported a link between cervical cancer and genital HPV infection. Genital HPV infections are now rec­ognized to be a major risk factor in at least $95\%$ of cervical cancers. 30 different HPV genotypes have been identified as causative of sexually transmitted diseases, most of which induce lesions in the cervix, vagina, vulva, penis, and anus, as the result of sexual contact. There is also direct evidence demon­strating that at least four of these genotypes are prerequisite factors in cervical cancer. The main aim of this review was to evaluate the current literature regarding the pathovirology, diagnostics, vaccines, therapy, risk groups, and further therapeutic directions for HPV infections. In addition, we reviewed the current status of HPV infections in South Korean women, as evidenced by our data.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.9-18
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• 2017

Nine bacilli with fibrinolytic activities were isolated from doenjang, a traditional Korean fermented soy food. Among them, RSB34 showed the strongest activity and was identified as Bacillus amyloliquefaciens by 16S rRNA and recA gene sequencing. During growth on LB up to 96 h, RSB34 showed the highest fibrinolytic activity ($83.23mU/{\mu}l$) at 48 h. Three bands of 23, 27, and 42 kDa in size were observed when the culture supernatant was analyzed by SDS-PAGE and 27 and 42 kDa bands by fibrin zymography. The gene encoding the 27 kDa fibrinolytic enzyme AprE34 was cloned by PCR. BLAST analyses confirmed that the gene was a homolog to genes encoding AprE-type proteases. aprE34 was overexpressed in Escherichia coli BL21(DE3) using pET26b(+). Recombinant AprE34 was purified and examined for its properties. The $K_m$ and $V_{max}$ values of recombinant AprE34 were $0.131{\pm}0.026mM$ and $16.551{\pm}0.316{\mu}M/l/min$, respectively, when measured using an artificial substrate, N-succinyl-ala-ala-pro-phe-p-nitroanilide. aprE34 was overexpressed in B. subtilis WB600 using pHY300PLK. B. subtilis transformants harboring pHYRSB34 (pHY300PLK with aprE34) showed higher fibrinolytic activity than B. amyloliquefaciens RSB34.

• Spatial Information Research
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• v.2 no.2
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• pp.189-196
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• 1994

Adaptive smoothing filter is a filter that averages out the intensities around the pixels of similar intensities while conserving the discontinuties. When human eyes rec-ognize a map, the brain can easily assign one color for each element such as road or building while computer distinguishes all the minute color differences even for one ele¬ment. We can approach to the solution by using the adaptive smoothing filter so that the machine can assign one color for each element as much as we want, and it is found to be a very essential tool foor map segmentation of urban areas. The filter is applied to a scanned map, and it is used to extract roads and residential areas.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.5
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• pp.620-631
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• 2015

A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC $43971^T$, Micrococcus luteus ATCC $4698^T$ and Escherichia coli ATCC $11775^T$ were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at $100^{\circ}C$), but the antimicrobial activity was eliminated after treatment at $121^{\circ}C$ for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory.