• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.5
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• pp.11-21
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• 2008

In recent years, time history analysis has been the method generally used for the seismic analysis of tall buildings with damping devices. When T is the natural period of the first vibration mode of the structure, the sum of the spectral acceleration of the earthquake ground motion is usually adjusted to that of the design response spectrum in the period ranging from 0.2T to 1.5T to meet the requirements of design code. However, when the ground motion is scaled according to the design code, the differences in the responses obtained by response spectrum analysis (RSA) and time history analysis (THA) of the structures increase as the natural period of the structure becomes longer. When time history analysis is performed by using ground accelerations that are scaled according to the design code, base shear is similar to that obtained from RSA, but other responses, such as displacements, drifts and member forces, are underestimated compared to RSA. If these results are adjusted by multiplying with the scale-up factor, the scaled responses become much smaller. Therefore, a scaling method of ground motions corresponding with the design code is proposed in this study, as a way of assisting structural engineers in generating artificial ground motions.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.2089-2092
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• 2007

Tantalum-containing metal oxides, well known for their efficiency in water splitting and H2 production, have never been used in visible light driven photodecomposition of H2S and H2 production. The present work is an attempt in this direction and investigates their efficiency. A mixed metal oxide, ZnFe2Ta2O9, with the inclusion of Fe2O3 to impart color, was prepared by the conventional ceramic route in single- and double-calcinations (represented as ZnFe2Ta2O9-SC and ZnFe2Ta2O9-DC respectively). The XRD characterization shows that both have identical patterns and reveals tetragonal structure to a major extent and a minor contribution of orthorhombic crystalline system. The UV-visible diffuse reflection spectra demonstrate the intense, coherent and wide absorption of visible light by both the catalysts, with absorption edge at 650 nm, giving rise to a band gap of 1.9 eV. Between the two catalysts, however, ZnFe2Ta2O9-DC has greater absorption in almost the entire wavelength region, which accounts for its strong brown coloration than ZnFe2Ta2O9-SC when viewed by the naked eye. In photocatalysis, both catalysts decompose H2S under visible light irradiation (λ ≥ 420 nm) and produce solar H2 at a much higher rate than previously reported catalysts. Nevertheless, ZnFe2Ta2O9-DC distinguishes itself from ZnFe2Ta2O9-SC by exhibiting a higher efficiency because of its greater light absorption. Altogether, the tantalum-containing mixed metal oxide proves its efficient catalytic role in H2S decomposition and H2 production process also.

• Tuberculosis and Respiratory Diseases
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• v.58 no.6
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• pp.600-606
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• 2005

Background : The development of bronchoscopic equipment along with the precision of radiographic techniques had reduced the mortality rate of patients with tracheobronchial foreign bodies but has been no change in the incidence of tracheobronchial foreign bodies since their introduction. The aim of this study was to assess the clinical characteristics of a tracheobronchial foreign body aspiration and to evaluate the efficacy of the treatment modality in children and adults. Methods : This is a retrospective review of 64 patients who underwent bronchoscopic procedures for the treatment of aspirated foreign bodies from December 1994 through March 2004 at the Chonnam national university hospital. Results : There were 47 males and 17 females, aged from 1 month to 78 years. Most of the patients had no underlying illness except for one patient with a cerebrovascular accident that contributed to the foreign body aspiration. The most common symptom was cough, which was noted in 54 patients (84.3%). The other presenting symptoms were dyspnea (48.8%), fever (20.3%), sputum (14%), vomiting (7.8%), and chest pain (4.6%). Those whose tracheobronchial foreign bodies were diagnosed more than 2 days after the aspiration (21 patients) were more likely to have pneumonia than those whose foreign bodies were diagnosed within 2 days (p = 0.009). Foreign bodies were visualized in the plain chest radiographs in 12 cases (18.8%), while others showed air trapping (21, 32.8%), pneumonia (15, 23.4%), atelectasis (7, 10.9%), and normal findings (9, 14.1%). The foreign bodies were more frequently found in the right bronchial tree (36) compared with the left bronchial tree (22, p = 0.04). In order to remove the foreign bodies, twenty (31.2%) cases were removed using flexible bronchoscopy, while 42 (65.6%) and 2 (3.2%) cases required rigid bronchoscopy and surgery, respectively. Conclusions : Tracheobronchial Foreign body aspiration had a bimodal age distribution in the infancy and old age around 60 years. They were found more frequently in the right bronchial tree. In addition, patients whose foreign bodies were diagnosed more than 2 days after the aspiration were more likely have a infection. Rigid bronchoscopy is the procedure of choice for uncooperative children and for those with foreign bodies lodged deeply in the small bronchial tree.

• Journal of the Korean Chemical Society
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• v.40 no.6
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• pp.445-452
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• 1996

Catalytic hydrogenation of ketones and aldehydes by RuH(NO)$L_3$ ($L_3$: $PPh_3$, PhP($CH_2CH_2PPh_2$)$_2$(etp)) was investigated to examine the reaction mechanism and the competence of hydridonitrosyl complexes as catalysts for organic synthesis. RuH(NO)$L_3$ showed catalytic activity for the hydrogenation and the activities of catalysts were dependent on the steric and electronic factors. The less the steric demands of the substrates become, the more activity the catalysts show. For the electronic effect, the more the partial positive charge on the carbonyl carbon atom in ketones becomes and the more the double bond character of carbonyl group in aldehydes becomes, the more active the catalysts are. These results reflect the difference of reaction mechanisms of two substrates, ketones and aldehydes. Catalytic activities of RuH(NO)(etp) and RuH(NO)($PPh_3$)$_3$ in the presence of extra $PPh_3$ toward hydrogenation showed the existence of a reaction pathway accompanied with the change of the bonding modes of NO ligand. The roles of excess $PPh_3$ change with increase of the mole ratio of $PPh_3$ to catalysts; prevention of ligand dissociation from comlexes → bases → ligands. The activity of RuH(NO)(etp) was lower than that of RuH(NO)($PPh_3$)$_3$ toward the hydrogenation of the same substrates mainly due to the structural difference. These catalysts showed the selectivity toward olefin hydrogenation over carbonyl groups in the competitive reaction.

• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.498-503
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• 2012

The aim of this study is to compare the total polyphenol, total flavonoid, and antioxidative activity among 5 cultivars of Korean pears cultivated in Korea. As a result of the analysis for the phenolic substance of 5 cultivars, such as Wonwhang, Sunwhang, Whangkeumbae, Chuwhang, and Shingo, the content of total polyphenol was higher in Shingo and Chuwhang, and the content of total flavonoid showed higher levels in Wonwhang and Sunwhang. In addition, this study found that DPPH radical-scavenging ability was the highest in Shingo and that the part of fruit skin showed more favorable reaction to radical ability than fruit flesh. It was also found that much better antioxidative activity was shown for the methanol solvent extraction than for the ethanol solvent extraction. The nitrite-scavenging ability showed the best for Wonwhang and Chuwhang of the cultivars and much better reaction for the methanol solvent extraction than for the ethanol solvent extraction just like the case of DPPH radical-scavenging ability. Further, nitrite-scavenging ability appeared much better reaction for the fruit skin than for the fruit flesh, and antioxidative activity dropped for the higher the range on the pH scale. From the results of this study, Korean pears are worthy of developing as a natural functional food and substance for beauty treatment through the research on bioactivity.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.741-747
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• 2007

In the azoospermic patients, there are many of undiagnosed factors related to genetic bases. Among them, Klinefelter's syndrome (47,XXY; KS) and Y-chromosomal microdeletion with normal karyotype(46,XY; YMNK) are the most frequent causes of male infertility. This research focused on the comparative analysis of YMNK (n = 66) and K5 (n = 30) patients suffered from male infertility in Korean population. We used the polymerase chain reaction (PCR) approach including 19 pairs of sequence-tagged site (STS) primers for detecting the Y-chromosomal microdeletion on AZFa, b, c regions, indicating that Y chromosomal microdeletions were almost evenly occurred in AZF all regions in Korean population. Comparative analysis indicated that 34.9% YMNK and 73.4% KS patients harbored the microdeleted Y-chromosome. It seems to be high instability of Y-chromosome in KS patients than that of YMNK infertility patients. Taken together, genome instability containing microdeletion could bring male infertility with the disturbance of normal spermatogenesis.

• Journal of Life Science
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• v.20 no.5
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• pp.683-690
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• 2010

The yeast strains of Saccharomyces diastaticus produce one of three isozymes of an extracellular glucoamylase I, II or III, a type of exo-enzyme which can hydrolyse starch to generate glucose molecules from non-reducing ends. These enzymes are encoded by the STA1, STA2 and STA3 genes. Another gene, sporulation-specific glucoamylase (SGA), also exists in the genus Saccharomyces which is very homologous to the STA genes. The SGA has been known to be produced in the cytosol during sporulation. However, we hypothesized that the SGA is capable of being secreted to the extracellular region because of about 20 hydrophobic amino acid residues at the N-terminus which can function as a signal peptide. We expressed the cloned SGA gene in S. diastaticus YIY345. In order to compare the biochemical properties of the extracellular glucoamylase and the SGA, the SGA was purified from the culture supernatant through ammonium sulfate precipitation, DEAE-Sephadex A-50, CM-Sephadex C-50 and Sephadex G-200 chromatography. The molecular weight of the intact SGA was estimated to be about 130 kDa by gel filtration chromatography with high performance liquid chromatography (HPLC) column. Sodium dedecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed it was composed of two heterogeneous subunits, 63 kDa and 68 kDa. The deglycosylation of the SGA generated a new 59 kDa band on the SDS-PAGE analysis, indicating that two subunits are glycosylated but the extent of glycosylation is different between them. The optimum pH and temperature of the SGA were 5.5 and $45^{\circ}C$, respectively, whereas those for the extracellular glucoamylase were 5.0 and $50^{\circ}C$. The SGA were more sensitive to heat and SDS than the extracellular glucoamylase.

• The Korean Journal of Mycology
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• v.26 no.1 s.84
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• pp.1-7
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• 1998

In order to find relationship within and between entomopathogenic species, analysis of protein band pattern in mycelia of 25 isolates was conducted by UPGMA. The results allowed differentiation of three groups on 85% similarity coefficient. Similarity coefficient within C. militaris was $0.787{\sim}1.000$, C. kyushuensis was 0.958-1.000 and C. pruinosa was 0.993-1.000. C210 and C298 isolates which had somewhat immersed perithecia, comparable to other C. militaris isolates, had 91% similarity. C108, C225-1 and C228 isolates pathogenic on Lepidopterous larvae had 89% similarity. Closely related species to C. militaris were C. kyushuensis and C. pruinosa. And similarity between C. pruinosa and C. kyushuensis was 88%. Similarity between C. bifusispora formed conidia on media and Paecilomyces tenuipes was 89%. C. scarabaeicola pathogenic specifically on adult Scarabaeidae had 82% similarity with above two species. C118 identified as C. militaris showed different protein banding patterns.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.411-416
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• 2002

Yogurt base was prepared from whole milk and skim milk added with 0.2∼1.0% (w/v) of Saururus chinensis(Lour.) Bail water extract (SCe) and fermented with lactic acid bacterias (the mixed strain of Streptococcas themophilus and Lactobacillus bulgaricus) at 37$\^{C}$ for 24 hr. Quality characteristics of the yogurt were evaluated in terms of acid production, number of viable cells, viscosity and sensory property during lactic acid fermentation. The composition of organic acids was also measured by HPLC. Addition of SCe stimulated the growth of lactic acid bacteria and remarkably enhanced the acid production. The viscosity and lactic acid content of yogurt were also increased by addition of SCe. The sensory score of yogurt added with 0.4% of SCe was significantly higher than other groups in taste and overall acceptability The storage abilities of yogurts added with SCe were relatively good at 5$\^{C}$ for 15 days.

• Journal of KIISE:Databases
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• v.37 no.6
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• pp.315-323
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• 2010

In Wireless Sensor Networks (WSNs), various Data-Centric Storages (DCS) schemes have been proposed to store the collected data and to efficiently process a query. A DCS scheme assigns distributed data regions to sensor nodes and stores the collected data to the sensor which is responsible for the data region to process the query efficiently. However, since the whole data stored in a node will be lost when a fault of the node occurs, the accuracy of the query processing becomes low, In this paper, we propose an in-network aggregation query processing method that assures the high accuracy of query result in the case of data loss due to the faults of the nodes in the DCS scheme. When a data loss occurs, the proposed method creates a compensation model for an area of data loss using the linear regression technique and returns the result of the query including the virtual data. It guarantees the query result with high accuracy in spite of the faults of the nodes, To show the superiority of our proposed method, we compare E-KDDCS (KDDCS with the proposed method) with existing DCS schemes without the data-loss correction method. In the result, our proposed method increases accuracy and reduces query processing costs over the existing schemes.