• Journal of the Korea Society for Simulation
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• v.27 no.4
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• pp.61-68
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• 2018

This paper deals with ground clutter model for FOD (foreign object debris) surveillance FMCW (frequency modulated continuous waveform) radar. In the FOD surveillance radar, it has received not only the signals reflected by FOD, but also the clutters of the surface of the runway and the grassland simultaneously. However, to detect the FOD, the clutter rejection algorithm is necessary because the RCS (radar cross section) of FOD is nearly same to RCS of the grassland. In addition, it is difficult to apply the MTI (moving target indicator) algorithm as the clutter rejection algorithm because both the FOD and the clutter coexist stationarily. Hence, to remove the stationary clutter, it is crucial to accurately generate clutter map considering the surface of road. In this paper, in order to generate the clutter map, the respective beat signal at every range bin is generated in the case of only the surface without FOD, and then the beat signal accumulated 100 times. And also, Weibull distribution is applied to the RCS value to take the scattering distribution of clutter into consideration. The simulation results show that FOD can be well detected by applying the generated clutter map to the FOD FMCW radar.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.99-104
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• 2009

The $\beta$-glucosidase gene from Streptomyces coelicolor A3(2) was cloned and expressed in Escherichia coli. The ORF consisted of 1377 nucleotides encoding 51 kDa in a predicted molecular weight. Effects of pH indicated that the $\beta$-glucosidase showed similar activity using $\alpha$-pNPG($\rho$-nitrophenyl-$\alpha$-D-glucopyranoside), $\beta$-pNPG($\rho$-nitrophenyl-$\beta$-D-glucopyranoside), and $\beta$-pNPF($\rho$-nitrophenyl-$\beta$-D-fucopyranoside) at range of pH 3 to 10, and high activity using $\beta$-pNPGA ($\rho$-nitrophenyl-$\beta$-D-galactopyranoside) from pH 5 to 10, especially, 3.3 times higher activity at pH 9. Effects of temperature indicated that the $\beta$-glucosidase showed low activity using $\alpha$-pNPG, $\beta$-pNPG, and $\beta$-pNPF from $20^{\circ}C$ to $70^{\circ}C$, and increased activity using $\beta$-pNPGA from $30^{\circ}C$ to $50^{\circ}C$, 1.8 times higher activity at $50^{\circ}C$ than at $30^{\circ}C$. According to activity determination of other substrates, the enzyme was active on daidzin, genistin, and glycitin, inactive on esculin and apigenin-7-glucose. The EDTA and DTT as reducing agents inhibited $\beta$-glucosidase activity, but SDS and mercaptoethanol did not inhibit. Monovalent or divalent metal ions such as $MnSO_4$, $CaCl_2$, KCl, and $MgSO_4$ did not inhibited $\beta$-glucosidase activity. $CuSO_4$ and NaCl showed low inhibition, and $ZnSO_4$ inhibited 3.3 times higher than control.

• Journal of Chest Surgery
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• v.36 no.12
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• pp.894-903
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• 2003

Protection against ischemia-reperfusion injury is crucial for successful transplantation of the lung. It has been known that nitric oxide has many favorable effects on the donor lungs but at the same time, has some potential side effects of cytotoxicity. In this regards, we investigated whether the administration of nitroglycerin could decrease ischemia-reperfusion injury in isolated rat lung reperfusion model for the confirmation of the effect of nitroglycerin, a donor of nitric oxide, on lung transplantation. Material and Method: 35 Sprague-Dawley species male white rats were used for this experiment. For nitroglycerin group (n=18), nitroglycerin was administered intravenously followed by mixed in flushing solution for preservation. As a control group (n=17), we used the same amount of normal saline. To evaluate the effect of nitroglycerin on the lung, heart-lung block was obtained, weighed and stored in University of Wisconsin Solution at 1$0^{\circ}C$ for 24 hours. In each group of the isolated lungs, reperfusion was carried out with Krebs-Hensleit-diluted human blood for 60 minutes. As parameters of the state of the isolated lung, peak inspiratory and pulmonary arterial pressures were continuously recorded. Oxygen and carbon dioxide tension of reperfusing blood were measured before and after 30, 60 minutes of reperfusion. After sixty minutes of reperfusion, protein content in bronchoalveolar lavage fluid was measured also for the evaluation of the degree of alveolar flooding. Lung myeloperoxidase activity was determined to verify the accumulation of neutrophils. Results: Although statistically significant differences were not noted in peak inspiratory and pulmonary arterial pressure between control and nitroglycerin group, latter group showed lowering tendency of pulmonary arterial pressure during the entire reperfusion period. Oxygen tension was higher (p<0.05) in nitroglycerin group compared with that of the control group, in contrast, there were no differences in carbon dioxide tension, protein content in bronchoalveolar lavage fluid and myeloperoxidase activity between the groups. In the examination of ultrastructural changes, nitroglycerin denoted the protective effect on the pulmonary architecture compared with that of control group. Conclusion: Collectively, on the bases of these experimental results, prior treatment of donor lung with nitroglycerin could result in better preservation of the lung. Consequently, these nitroglycerin preserved lungs are thought to be more suitable for successful transplantation of the lung.

• Korean Journal of Psychosomatic Medicine
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• v.26 no.2
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• pp.102-111
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• 2018

Objectives : This study aimed to investigate the relationship between personality characteristics of medical students at their admission and the level of depression, anxiety, and resilience at their third year. Methods : Self-reported questionnaires were conducted to the students at the beginning of the first year and the third year. When the students in their first year, they performed the personality assessment inventory, the Beck depression inventory, and the Beck anxiety inventory. When they were in the third year, the students answered the composite Scale of morningness and Conner-Davidson resilience scale-10 in addition to the BDI and BAI. Multiple linear regression analyses were performed to identify predictors of the level of depression, anxiety, and resilience. Results : Of the subscales of depression in the PAI, the physiological depression (${\beta}=-0.285$, p=0.049) associated with increase in the depression from the first to the third year. Among the anxiety-related disorder subscale in the PAI phobia (${\beta}=0.119$, p=0.022) and traumatic stress (${\beta}=0.375$, p=0.007) associated with the level of depression at third grade. Somatization (${\beta}=0.631$, p<0.001) in the PAI associated with the level of anxiety at third year. The anxiety (${\beta}=-0.531$, p<0.001) in the PAI was positive associated with the resilience at third grade. Conclusions : This study showed that certain personality characteristics at admission had significant relationships with the level of depression, anxiety, and resilience at the third grade medical students.