• Journal of Korean Society on Water Environment
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• v.27 no.5
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• pp.625-633
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• 2011

A long-term water quality monitoring in the Han River Basin reveals a consistent increasing trend for the concentration of refractory organic matter (R-OM) in major monitoring sites of the watershed. Because the determination of R-OM concentrations typically requires a long time of microbial incubation, it is essential to present the estimation indices for R-OM for an efficient watershed management. In this study, a number of surface water samples were classified into three groups, each of which were collected from Lake Paldang, rivers at rain and non-rain events, respectively. The corresponding R-OM concentrations were correlated with biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC) concentrations as well as ultraviolet and fluorescence intensities of the filtered samples. Among the traditional organic matter parameters, TOC exhibited the highest correlation coefficient with the R-OM concentrations regardless of the types of the sample groups. The equations for conversing TOC into R-OM concentrations were finally suggested as $0.43{\times}TOC+1.12$, $0.44{\times}TOC+0.61$, $0.24{\times}TOC+1.28$ for river samples at rain and non-rain events, and lake samples, respectively. TOC-BOD(C), the values of the TOC concentrations subtracted by carbon-converted BOD concentrations, was a good index for estimating the absolute concentrations of R-OM. UV absorbance at 254 nm was well correlated with R-OM concentrations of river samples while fluorescence intensities at 350 nm showed an excellent relationship with R-OM concentration of the lake samples. Our results suggests that simple spectroscopic parameters could be applied for in-situ monitoring tool techniques in watersheds.

• Journal of Animal Science and Technology
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• v.63 no.1
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• pp.125-136
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• 2021

Bovine coronavirus (BCoV) is associated with severe diarrhea, dehydration, and depression, which result in significant economic damages in the dairy and beef cattle industries worldwide. However, differences in the gut microbiota structure and their correlations with differing physiological parameters between BCoV-infected calves with diarrhea and recovered calves are not well understood. In this study, fecal specimens were collected from 10 post-weaned calves, before and after 2 months of fluid therapy, and the samples were used for microbiota analysis. Following recovery, the alpha-diversity profiles (observed operational taxonomic units [OTUs], and Chao1, Shannon, and Simpson indices) changed significantly when compared with those of calves with diarrhea. Beta-diversity analysis exhibited significant differences in gut microbiota compositions between calves with diarrhea and those in the recovered state. The abundances of eight phyla and thirteen genera in feces changed markedly after restoration of BCoV diarrhea. In addition, our correlation study clearly revealed that increased abundances of the genera Caproiciproducens, Pseudoflavonifractor, and Oscillibacter negatively correlated with serum glucose, and phosphorus levels, but positively correlated with serum chloride in calves with diarrhea, whereas increased abundances of the genera Peptostreptococcaceae;Clostridium (Clostridium cluster XI), Intestinibacter, Cellulosilyticum, Ruminococcus, Romboutsia, Paeniclostridium, Clostridiaceae;Clostridium and Turicibacter in recovered calves showed the opposite pattern. These results suggest that structural changes of the gut microbiota after recovery from BCoV infection correlate with changes in physiological parameters. In conclusion, our data provide evidence of gut microbiota-composition changes and their correlations with the physical profiles of post-weaned calves, before and after fluid therapy for BCoV-related diarrhea.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.212-219
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• 2021

The aims of this study were to measure the ultrasonographic biometry of genitalia of the indigenous rams and observe the relationship of biometry on semen parameters. The epididymal volume was significantly reduced (p < 0.01) after semen collection compared with before collection for both left and right part in all rams. The cumulative results showed that although there was no significant difference in length, width and volume of epididymis between before and after semen collection, however the values were lower after collection. The epididymal length was significantly correlated with epididymal volume (p < 0.01), semen motility (p < 0.05) and semen morphology (p < 0.01). Epididymal width was only significantly correlated with epididymal volume (p < 0.01) not with the semen parameters. Epididymal volume had a significant correlation only with semen morphology (p < 0.01).The scrotal circumference had the significant correlation with semen density, mass activity, concentration and motility (p < 0.01). The epididymis had the similar or slightly increased echogenicity as compared to the normal testis. During whole study, some white spots were found on testis which did not affect the semen quantity and quality. Significant variation was observed only for semen concentration and motility among the rams (p < 0.05). The overall normal morphology was 90.5 ± 4.6% with highest percentage of coiled tail abnormalities.

• BMB Reports
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• v.28 no.5
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• pp.464-470
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• 1995

Quinolone antibiotics are DNA gyrase inhibitors, but their bactericidal action seems to involve more than the inhibition of DNA gyrase activity. Hence, the potentially crucial factors among possible mechanisms of quinolone action; cleavable complex formation, inhibition of DNA synthesis, and induction of SOS response were investigated. These parameters were measured in an Escherichia coli strain exposed to quinolones in the logarithmic growth phase, and correlated with the bactericidal activity of quinolones. Cleavable complex formation proved to be the factor most related to bactericidal action. Inhibition of DNA synthesis was substantially correlated with bactericidal activity, but induction of SOS response was least correlated with bactericidal activity. Therefore, it was concluded that quinolones exert bactericidal action primarily through cleavable complex formation, and subsequent unknown cellular processes together with inhibition of DNA synthesis contribute to the bactericidal activity of quinolones.

• Asian Journal of Atmospheric Environment
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• v.5 no.2
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• pp.105-112
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• 2011

In order to investigate the effects of local and synoptic meteorological conditions on urban scale particulate air pollutants observed over the Busan coastal area, power spectrum analysis was applied to observed particulate matter with an aerodynamic diameter $\leq10\;{\mu}m$ ($PM_{10}$) for the period from 1 October, 1993 to 31 December, 2004. Fast Fourier Transform (FFT) analysis was used to obtain the hourly mean observed $PM_{10}$ concentrations to identify different periodicity scales of $PM_{10}$ concentrations. The results showed that, aside from the typical and well-known periodicities such as diurnal and annual variations caused by anthropogenic influences, three other significant power spectral density peaks were identified: 7-day, 21-day and 2.25-year periodicities. Cospectrum analysis indicated that the seven-day variations were closely related to the synoptic meteorological conditions such as weak wind speed, which are relevant to the stagnant high pressure system slowly passing through the Korean Peninsula. The intra-seasonal 21-day variation was negatively correlated with wind speed but was consistently positively correlated with relative humidity, which is related to aerosol formation that can be achieved as a result of the hygroscopic characteristics of aerosols. However, the quasibiennial 2.25-year variation was correlated with the frequency of Asian dust occurrence, the periodicities of which have been recorded inter-annually over the Korean Peninsula.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2973-2978
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• 2012

Background: Cancer stem cells (CSC) have been described in a variety of malignancies, including breast carcinomas. Among several markers, aldehyde dehydrogenase 1 (ALDH1) has been identified as reliable for breast cancer stem cells. Knockdown of BRCA1 in primary breast epithelial cells leads to an increase in cells expressing ALDH1. Methods: We examined 127 breast carcinomas for expression of ALDH1, using immunohistochemistry and correlated with clinicopathological parameters as well as the BRAC1 status. Results: Comparing the results for both ALDH1 and BRCA1 expression showed a significant inverse association between the two, indicating that reduced BRCA1 was more often seen in breast cancer cells expressing ALDH1 (p-value = 0.044). A total of 24/110 (22%) of tumours displayed the ALDH1 + / BRCA1 -/low phenotype, which showed a trend for a relation with a high grade (p-value= 0.056). Cytoplasmic expression of ALDH1 was not correlated with tumour characteristics. Conclusion: Taken together, our findings suggest that increased ALDH1 is inversely correlated with decreased BRCA1 in a series of unselected breast carcinomas. Therefore, ALDH1 positive (cancer stem) cells with reduced BRCA1 phenotype may indicate a subset of patients for whom specific targeting of the CSC marker ALDH1 and more aggressive adjuvant treatment is appropriate.

• Journal of Nutrition and Health
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• v.31 no.1
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• pp.28-35
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• 1998

This study was done to investigate the relationship between ultrasonograph fat density (ULFD) using objective measurement and serum enzymes for testing liver function in 101 healthy adults(43 males and 58 females). Average serum enzyme activities in males and females were GOT27.111U/L and 22.46IU/L, GPT 34.06IU/L and 18.501U/L, and ${\gamma}$-GTP 37.67IU/L and 17.201U/L, respectively. Males showed significantly higher activities of GPT and ${\gamma}$-GTP than females. ULFD of the obese group (BMI$\geq$25) was significantly higher than that of the nonobese group. GOT, GPT, and ${\gamma}$-GTP tended to be high in the obese group. GPT and ${\gamma}$-GTP of the high TG group (TG$\geq$170) tended to be markedly high for males, but not for females. GPT was positively correlated with ULFD, body weight , and weight-to-height, ratio, and ${\gamma}$-GTP was positively correlated with body weight, weight-to-height ratio. BNI, and KI. ULFD and ${\gamma}$-GTP were positively correlated with serum TG. These results suggests that , among serum enzymes for testing liver function, GPT has a close relationship with ULFD using objective measurement, while GOT does not. Also , ${\gamma}$-GTP has a close relationship with parameters for obesity.

• ETRI Journal
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• v.46 no.2
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• pp.184-193
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• 2024

This paper presents the performance evaluation of an amplify-and-forward (AF) relay-assisted multiuser multiple input-multiple output (MU-MIMO) downlink transmission system for correlated fading channels. The overall system performance was improved by incorporating a double-quadrature spatial modulation (DQSM) scheme. The bit error rate (BER) performance and detection complexity of the AF-MU-MIMO-DQSM system were analyzed and compared with those of a conventional AF-MU-MIMO system under the same conditions and parameters. The results showed that the correlated fading channel severely affected the performance of systems with higher spectral efficiency (SE). Considering an SE of 12 bpcu/user, the AF-MU-MIMO-DQSM system yielded a gain of up to 3 dB in BER performance compared with that of its conventional counterpart for the analyzed cases. In terms of detection complexity, the AF-MU-MIMO-DQSM system showed a reduction of up to 56 % compared with that of the conventional system for the optimal maximum likelihood detection criterion.

• Journal of The Korean Astronomical Society
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• v.52 no.4
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• pp.133-144
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• 2019

We develop forecast models of daily probabilities of major flares (M- and X-class) based on empirical relationships between photospheric magnetic parameters and daily flaring rates from May 2010 to April 2018. In this study, we consider ten magnetic parameters characterizing size, distribution, and non-potentiality of vector magnetic fields from Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Imager (HMI) and Geostationary Operational Environmental Satellites (GOES) X-ray flare data. The magnetic parameters are classified into three types: the total unsigned parameters, the total signed parameters, and the mean parameters. We divide the data into two sets chronologically: 70% for training and 30% for testing. The empirical relationships between the parameters and flaring rates are used to predict flare occurrence probabilities for a given magnetic parameter value. Major results of this study are as follows. First, major flare occurrence rates are well correlated with ten parameters having correlation coefficients above 0.85. Second, logarithmic values of flaring rates are well approximated by linear equations. Third, using total unsigned and signed parameters achieved better performance for predicting flares than the mean parameters in terms of verification measures of probabilistic and converted binary forecasts. We conclude that the total quantity of non-potentiality of magnetic fields is crucial for flare forecasting among the magnetic parameters considered in this study. When this model is applied for operational use, it can be used using the data of 21:00 TAI with a slight underestimation of 2-6.3%.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1213-1218
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• 2007

The brake judder comes from non-uniformities in the tire/wheel assembly caused by mechanical effects such as a brake torque variation (BTV). A disc thickness variation (DTV) related with the kinematic behavior of the disc was investigated a main source of BTV. In this study, a dynamic model with brake corner assembly of full vehicle using MSC.ADAMS was correlated by experiment of judder phenomenon. Judder was generated and correlated systematically by judder experiment in chassis and brake dynamometer from variation in the thickness of the disc. Also it has been found a judder transfer path and variation of the braking pressure. Through analysis of transfer function and movement of subsystem caused by BTV generation, design parameters have been found. Based on the results obtained from parameter study of suspension module, the effective design process and developed model with brake corner assembly was suggested for vibration reduction of steering wheel caused by the judder phenomenon.