• Korean Journal of Optics and Photonics
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• v.33 no.4
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• pp.167-176
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• 2022

Adaptive optics (AO) systems compensate for atmospheric disturbance, especially phase distortion, by introducing counter-wavefront deformation calculated from real-time wavefront sensing or prediction. Because AO system implementations are time-consuming and costly, it is highly desirable to estimate the system's performance during the development of the AO system or its parts. Among several techniques, we mostly apply statistical analysis, computational simulation, and optical-bench tests. Statistical analysis estimates performance based on the sum of performance variances due to all design parameters, but ignores any correlation between them. Computational simulation models every part of an adaptive optics system, including atmospheric disturbance and a closed loop between wavefront sensor and deformable mirror, as close as possible to reality, but there are still some differences between simulation models and reality. The optical-bench test implements an almost identical AO system on an optical bench, to confirm the predictions of the previous methods. We are currently developing an AO system for a 1.6-m ground telescope using a deformable mirror that was recently developed in South Korea. This paper reports the results of the statistical analysis and computer simulation for the system's design and confirmation. For the analysis, we apply the Strehl ratio as the performance criterion, and the median seeing conditions at the Bohyun observatory in Korea. The statistical analysis predicts a Strehl ratio of 0.31. The simulation method similarly reports a slightly larger value of 0.32. During the study, the simulation method exhibits run-to-run variation due to the random nature of atmospheric disturbance, which converges when the simulation time is longer than 0.9 seconds, i.e., approximately 240 times the critical time constant of the applied atmospheric disturbance.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.176-184
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• 2018

In the present study, we investigated the antioxidative properties, cellular protective effects and component analyses of 50% ethanol extract, ethyl acetate fraction and aglycone fraction obtained from Lysimachia christinae Hance (L. christinae Hance). In the evaluation of antioxidative properties, the free radical scavenging activities ($FSC_{50}$) of 50% ethanol extract, ethyl acetate fraction and aglycone fraction were 146.8, 22.2 and $27.2{\mu}g/mL$, respectively and total antioxidant capacities ($OSC_{50}$) were 29.3, 2.9 and $4.5{\mu}g/mL$, respectively. The ethyl acetate fraction showed the highest free radical scavenging activity and total antioxidant capacity. Also, the cellular protective effects (${\tau}_{50}$) of 50% ethanol extract, ethyl acetate fraction and aglycone fraction on $^1O_2$ induced photohemolysis of human erythrocytes were 26.9, 57.5 and 103.9 min at $5{\mu}g/mL$, respectively. In particular, ${\tau}_{50}$ of the aglycone fraction exhibited a higher cellular protective effect than that of (+)-${\alpha}$-tocopherol (37.7 min). The cell viability of the ethyl acetate fraction on the UVB-induced cell damage increased up to 90.1%. In addition, the ethyl acetate fraction ($5-25{\mu}g/mL$) showed cellular protective effects on the $H_2O_2-induced$ cell damages in a dose-dependent manner. TLC, HPLC, UV-vis spectroscopy and LC-MS were used to analyse components of the ethyl acetate fraction and the main components were quercetin, kaempferol and their glycosides. In conclusion, L. christinae Hance extract/fraction can function as antioxidants to protect the skin exposed to UV radiation and may also be used as a novel functional cosmetic material, for example, an antioxidant against skin photoaging.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.290-298
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• 1992

Although early diagnosis of urinary tract infection is important, the radiologic evaluation is still controversial because of the low sensitivity and the lack of cost-effectiveness. This study was carried out to evaluate the clinical utility of high resolution triple head $^{99m}Tc-DMSA$ SPECT imaging in urinary tract infection. We prospectively performed $^{99m}Tc-DMSA$ planar and SPECT imaging, ultrasound of kidney (US), intravenous pyelography (IVP) and voiding cystourethrography (VCU) in all 60 adult patients with UTI [26 with first episode of acute pyelonephritis (APN), 22 with recurrent APN, and 12 persistent asymptomatic pyuria] and 25 normal persons. To assess reversibility of the renal cortical defect (RCD), $^{99m}Tc-DMSA$ SPECT was repeated 1 to 8 months later in those patients with abnormal initial findings. Overall detection rate of $^{99m}Tc-DMSA$ SPECT imaging was 83% (50/60), but planar, US, IVP and VCU showed abnormal findings in 68%, 28%, 32% and 13%, respectively. 25 out of 27 patients with normal or single RCD were all normal in other radioligic studies. Only two patients showed vesicoureteral reflux (VUR) on VCU (grade I) and mild hydronephrosis on IVP. But, high proportion of those with multiple RCD showed abnormal findings on US (17/33), IVP (18/33), and VCU (7/33): 67% in any of these 3 studies. Especially, 3 out 7 patients with VUR showed multiple RCD on $^{99m}Tc-DMSA$ SPECT without any abnormality on IVP or US. 25 normal persons showed normal findings in all studies except one false positive finding on $^{99m}Tc-DMSA$ SPECT imaging. Follow-up $^{99m}Tc-DMSA$ SPECT was done in 28 patients (13 with single RCD, 15 with multiple RCD). All 13 patients with single RCD showed improvement. Those with multiple RCD presented improvement in 4, no change in 10, and aggravation in 1 on follow-up studies. With these results, we conclude: 1) $^{99m}Tc-DMSA$ SPECT imaging is superior to planar imaging, US, IVP or VCU in detection of renal lesion in urinary tract infection. $^{99m}Tc-DMSA$ SPECT is useful as a initial diagnostic tool in adult patients with urinary tract infection. 2) The multiple RCD on $^{99m}Tc-DMSA$ SPECT represent the high probability of irreversible tissue change and need of extensive urological work-up.

• Journal of Life Science
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• v.26 no.8
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• pp.936-942
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• 2016

As the incidence of environmental diseases is increasing due to harmful environmental factors, there is a rising interest in developing eco-friendly materials for housing. In this study, we sought to develop antimicrobial interior fabric blind materials by employing ethanol extract of a medicinal plant Zanthoxylum piperitum DC. As determined by the disc diffusion method, the zones of inhibition of the pericarp ethanol extract at a concentration of 5 mg/disc against Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus mutans were 13.5±1.5 mm, 14.0±0.5 mm and 15.0±0.1 mm, respectively, whereas the leaf ethanol extract (5 mg/disc) against K. pneumoniae, S. aureus, and S. mutans were 12.8± 0.3 mm, 13.5±1.0 mm, and 12.0±0.1 mm, respectively. The IC₅₀ of the leaf ethanol extract against K. pneumoniae, S. aureus and S. mutans were about 0.5 mg/ml, 0.1 mg/ml and 1.0 mg/ml respectively. To examine whether the leaf ethanol extract possessing antibacterial activity of Z. piperitum DC can be applicable to production of antimicrobial fabric blind materials, the fabrics treated with either 1.0% or 2.0% of the leaf ethanol extract were tested for antibacterial activity against K. pneumoniae and S. aureus using International Standard Fabrics Test Method. The results indicate that the fabric treated with the ethanol extract of Z. piperitum DC possesses an excellent antimicrobial activity against both pathogenic bacteria. These results suggest that Z. piperitum DC may be applicable to producing functional fabrics which are effective in reducing the harmful bacterial factors in indoor environments.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.299-310
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• 2019

The eating quality of rice is one of the main concerns of rice breeding programs in many countries, especially in japonica rice cultivation areas. To select new resources with high eating quality from Korean native japonica rice, we evaluated a total of 76 varieties, including 47 native rice resources (26 landraces + 21 weedy rice) of Korea. In this study, all eating quality traits varied widely among the native resources, and some of the native resources revealed a high evaluation score in the palatability, expected eating quality, and physicochemical traits among the tested whole-plant materials. From the results, we selected two landraces (Sangdo and Waebyeo) and three weedy rice varieties (Hoengseongaengmi3, Namjejuaengmi6, and Wandoaengmi6) as promising resources for improvement of rice eating quality. Specifically, Wandoaengmi6 presented potential as a key breeding material for improving the eating quality of Korean rice cultivars, having the best evaluation results in palatability score (PS 0.83) from the sensory test and glossiness value (GV 81.8) from the Toyo taste meter of cooked rice. Given the urgent need to overcome the constraint of the narrow genetic background of Korean japonica rice, the results could be a practical solution for exploring new opportunities for improving rice eating quality through the expansion of genetic resources.

• Journal of agriculture & life science
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• v.45 no.5
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• pp.63-71
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• 2011

This study was conducted to determine the effects of increasing the dietary levels of conjugated linoleic acid (CLA) which is produced from bio diesel by-products, on milk yield, milk composition, and blood metabolites of mid-lactating dairy cows. A total of 20 mid-lactating dairy cows ($631{\pm}25.0kg$) were assigned to one of four treatment groups and fed twice daily an equal amount of a basal diet ($NE_L$ 32 Mcal/d, CP 17%) contained 12kg/d of concentrate, 15kg/d of corn silage and 4kg/d of the hay mixture (tall fescue+orchard grass). Conjugated linoleic acid were fed for 2 weeks of adaptation periods and 4 weeks of collection periods at 0 (Control), 50 (T1), 100 (T2) and 150g/d (T3), respectively. By the increases of dietary CLA supplementation, milk yield and 4% fat corrected milk increased, whereas milk fat content decreased (p<0.05). The concentrations of stearic acid and oleic acid decreased with increasing dietary CLA supplementation, while the concentrations of total CLA increased (p<0.05). In conclusion, this study shown that the supplementation of dietary CLA manufactured from bio diesel by-products could improve milk yield and CLA concentrations of milk in mid-lactating dairy cows.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.83-89
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• 2010

The objective of this study was to investigate the effect of the environmental and genetic factors on the carcass traits of Korean cattle. We have used the data of 22,954 Korean cattle slaughtered from 2005 to 2009 in Gyeongnam region and estimated the genetic parameters of 36,868 cattle including the pedigree individuals by means of EM-REML analytical method. In summary, the heritability of the carcass weight, eye muscle area, backfat thickness and marbling score was 0.39, 0.30, 0.33 and 0.62, respectively. The carcass weight and the eye muscle area showed high correlation between them with the genetic correlation of 0.86 and the phenotypic correlation of 0.72. The high heritability of marbling score is assumed to be the result of focusing the breed improvement on the quality of the meat. Through this study, it is considered that the Korean cattle in Gyeongnam region are improving, which will thus contribute to the increase of the farmer's income. Additional study on the economic trait must be carried out to obtain clearer results that will lead to further improvement of Korean cattle.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.611-615
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• 2011

'Manjong' is a new japonica rice cultivar developed in 2009 derived from a cross between 'Yeongdeog34' and 'Nampyeongbyeo' at the Department of Functional Crop, NICS, RDA. This cultivar is suitable for the double cropping system after the cash crop cultivation. Heading date of 'Manjong' is later than 'Keumobyeo' under the late transplanting cultivation on July 10. It has high grain fertility under cold conditions and low premature heading. One of the distinguishing characteristics of this variety is its resistance to major diseases like leaf blast and rice stripe virus disease. However, it shows susceptibility to major insect pests and bacterial blight disease. Milled rice kernels are translucent with non-glutinous endosperm and have 7.2% protein and 18.7% amylose contents. Ripening ratio and head rice ratio is very higher than those of 'Keumobyeo'. The palatability of cooked rice is also better than 'Keumobyeo'. The milled rice yield of 'Manjong' in local adaptability tests after harvest of the cash crop is $4.81MT\;ha^{-1}$. This cultivar is suitable for planting in the plain paddy fields of Honam and Yeonnam regions in Korea.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.615-622
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• 2010

A new rice cultivar, 'Joami', was developed by the rice breeding team of Sangju Substation, National Institute of Crop Science (NICS), Rural Development Administration. It was selected by a bulk and pedigree methods from a cross-combination among 'Sambaegbyeo', 'Yukara', and 'Tonggae112'. A promising line of YR20557-1-1-3-B-3 was designated as 'Sangju 36' in 2006. Local adaptability test of 'Sangju 36' was conducted at ten sites throughout the Korean peninsula during three years from 2006 to 2008. 'Sangju 36', thereafter, was registered as 'Joami' in 2008. The cultivar headed on July 30 in the test of local adaptability. Endosperm of 'Joami' is translucent with clear chalkiness and has 5.4% higher head rice ratio than that of 'Odaebyeo'. The yield potential of 'Joami' in milled rice is about 5.40 MT/ha under ordinary fertilizer level of local adaptability test, which was 6% higher than that of 'Odaebyeo'. In an alpine area of Korea, the rice variety needs a cold tolerance and a resistance to blast disease. 'Joami' showed a tolerance reaction at Chuncheon cold tolerance screening nursery and exhibited resistance reaction to blast disease in nation-wide disease screening nursery. Therefore, 'Joami' would be well adaptable to mid-mountainous area at central and southern part of Korean peninsula.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.415-423
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• 2018

Rice panicle architecture is an important factor affecting yield potential. Korean rice cultivars have a narrow genetic background for panicle architecture. To enhance the yield potential of Korean rice cultivars, we developed and characterized rice lines with new panicle architecture. Rice with improved panicle architecture has clustered spikelets and dense panicles (CD type). CD rice was derived from a cross between "Binhae Col.#1" carrying dense panicles, and "ARC10319" that has the clustered spikelets gene (Cl). CD rice lines had short and semi-erect panicles with two to five high density spikelets clustered at the tips of primary and secondary rachis branches. CD rice lines had dramatically increased numbers of spikelets; almost twice as many as those of Korean rice cultivars. The increase in spikelet number was mainly caused by the increased spikelets and branches on secondary rachises compared to those on primary rachises. The increase in spikelet number was expected to enhance the yield of CD rice by expanding sink capacity. However, the yield of selected lines; CD9, CD27, CD34, and CD39, did not reach the level of the Korean high-yielding cultivars "Boramchan" and "Hanareum2," due to the reduction in panicle number and grain weight, and poor ripening. Although no substantial yield increase was observed in CD rice, the panicle architecture of CD rice, clustered spikelets, and dense panicles could be new genetic resources as breeding material for diversifying panicle architecture and enhancing yield potential.