• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.117-124
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• 2015

Purpose: The purpose of this study was to compare the accommodative function of young adult in their 20s wearing monovision, modified monovision, and aspheric multifocal contact lenses at near task. Methods: Thirty young adults ($23.53{\pm}2.37years$) were fitted with monovision, modified monovision (the application of single vision contact lenses and center-near low addition aspheric multifocal contact lenses), and aspheric center-near multifocal contact lenses. After wearing these modalities during a week for adaption, and after watching visual display at computer for inducing accommodative pressure for 1 hour. The following assessments of accommodative function were made: contrast visual acuity (VA) at distance and near; accommodative response; near accommodative facility; and negative relative accommodation (NRA)/positive relative accommodation (PRA). All measurements were carried out binocularly. Results: In binocular distance VA with contrast of 10%, monovision was the worst among the four modalities (p=0.005). In accommodative response at 1 m (1.00 D), monovision was the lowest (p<0.05) and accommodative response at 40 cm (2.50 D) with monovision was lower than that of modified monovision and multifocal contact lens (p<0.05). We also found that there were no significant differences in accommodative facility and NRA/PRA among the four modalities. Conclusions: In young adult (20s), monovision with low add reduced the accommodative response at near task, however, modified monovision and multifocal lens with center-near type did not affect accommodative relaxation.

• Korean Journal of Plant Resources
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• v.22 no.1
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• pp.5-12
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• 2009

Seed priming is a useful technique for rapid and uniform seed germination as well as early seedling establishment. This experiment was conducted to find out the optimum condition for Sorbus alnifolia seed priming with four concentrations of four reagents in germination property and seedling growth performance. The results are summarized as follows: Percent germination (PG) varied 2.67% to 24.67%, and S. alnifolia seeds had the highest PG in the treatment that were primed in 100mM $KNO_3$ solution for 2 days. Mean germination time was the shortest in 200 mM $KNO_3$ solution for 2 days. Seed priming with $KNO_3$ solutions increased germination speed (GS) and germination performance index (GPI) compared with non-primed seeds. Especially seed primed with 100 mM $KNO_3$ solution for 2 days showed the highest GS and GPI. The highest relative growth rate (RGR) and seedling vigor index (SVI) was significantly (p<0.05) different from the control and other treatments, respectively. RGR of height (0.0071) and root collar diameter (0.0141) of seedling from primed seeds were the highest in 400 mM NaCl solution for 2 days. The highest SVI (5.43) was observed in the seedlings from seeds primed in 100 mM $KNO_3$ solution for 2 days. Consequently, the optimum reagent and concentration were $KNO_3$ and 100 mM for the effective germination and seedling growth in S. alnifolia

• Journal of Conservation Science
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• v.37 no.5
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• pp.451-463
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• 2021

In this study we conducted component analyses of portable XRF detectors using four Au-Cu alloy standard samples to improve their accuracy by drawing up a calibration curve based on ICP-OES standard values. The portable XRF analysis found absolute errors of 0.3 to 3.7 wt% for Au and 0.2 to 8.2 wt% for Cu, confirming that the error range and standard deviation differed from one detector to another. Furthermore, the calibration curve improved their accuracy, such that the relative error rates of Au and Cu decreased from 9.8% and 14% to 3.5% and 3.7%, respectively. Accordingly, an experiment to confirm the calibration curve was conducted using unknown samples, finding that the measured values of the unknown samples fell on the calibration curve. Therefore, to accurately analyze the components of metal cultural heritage items, it is necessary to prepare a calibration curve for each element after checking whether the detector is suitable for the artifact.

• Korean journal of applied entomology
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• v.62 no.3
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• pp.139-147
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• 2023

Leaf-spray in vitro bioassays appraise new aphicidal formulations for managing deleterious plant-feeding aphids. The formulation may utilize alternative and integrated strategies. However, leaf spraying even under controlled conditions may affect aphid reproduction and mortality. This study examines leaf spray applications for optimum and reproducible aphicidal results using tobacco leaves overlaid on cotton fabric or water agar surfaces. Infestation of the undersides of tobacco leaves with nymphs of green peach aphids was used in the assays. Spray distance and volume were optimized using water-sensitive paper to ascertain the best surface coverage. Overlays of the leaves on water agar caused less mortality and greater reproduction than the use of cotton fabric. The relative humidity of the insect-rearing chambers changed with the watering regime for the insect - rearing chambers with cotton fabric; 60% relative humidity was optimal. Relative humidity was not affected by the concentration of agar in the water agar chambers. Applications of the chemical aphicidal standard, Sulfoxaflor, under the optimized conditions exhibited similar times for lethality although the rate was faster with leaves on the cotton fabric than on water agar. These studies establish reproducible and sensitive techniques for assessing the lethality and effects on reproduction of potential aphicidal products.

• Journal of Climate Change Research
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• v.4 no.3
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• pp.235-244
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• 2013

Carbon dioxide emission estimation methods consist of four tiers according to the IPCC guideline. In this study, estimated results by tier 3 and tier 4 were compared with the theoretically calculated $CO_2$ emissions based on the mass balance approach for a gas fired power plant between March and May 2011. It was found that the relative differences were upto 17% between the measured emissions by tier 4 and theoretically estimated emissions, while the results of tier 3 were similar to those from theoretically estimated ones. The comparisons suggested the possibility of misestimation due to replacing missing, abnormal, or invalid data in continuous emissions monitoring system. When using only the data without those missing, abnormal, or invalid data, the relative differences decreased somewhat but still showed consistent differences depending on the stack. It is suggested that this differences might be due to the accuracy of the measurement instruments for the tier 4, especially, for the flow rate measurement instrument.

• Korean Journal of Environment and Ecology
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• v.15 no.4
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• pp.394-400
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• 2002

A mixed forest community of broad-leaved trees in Guryongsan area was studied to determine the adequate number of plots of tree and shrub strata for investigating forest community structure. Fifteen 10m$\times$10m plots were set up in the tree stratum and fifteen 5m$\times$5m plots were set up in the shrub stratum. Species-area curves and performance curves were made from vegetation analysis of the plots. In tree stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the same percentage in number of species was five. In tree stratum, minimum number of plots where a given percentage increase in nuts her of plots produced less than the half of the percentage increase in number of species was ten. In tree stratum, minimum number of plots where the dominant species was distinguished from the subdominant species was four In tree stratum. minimum number of plots where the subdominant species were distinguished from each other was eight. In tree stratum, the difference of species diversity(H') between seven or more plots and total fifteen plots was less than 0.05 Similarity index was more than 80% between aye or more plots and total fifteen plots, and more than 90% between nine or more plots and total fifteen plots. In shrub stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the same percentage in number of species was five . In shrub stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the half of the percentage increase in number of species was twelve. In shrub stratum. minimum number of plots where the dominant species was distinguished from the subdominant species was four. In shrub stratum, the minimum number of plots where the subdominant species were distinguished from each other was thirteen. In shrub stratum, the difference of species diversity(H') between six or more plots and total fifteen plots was less than 0.05. Similarity index was more than 80% between five or more plots and total fifteen plots, and more than 90% between nine or more plots and total fifteen plots. It may be given as a conclusion that adequate number of 10m$\times$10m plots for the tree stratnm was about 5 in general acse and 10 in case of requiring more accuracy, and that the adequate number of 5m$\times$5m plots for ahrub stratum was about 5 in general case and 13 in case of requiring more accuracy.

• Tuberculosis and Respiratory Diseases
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• v.46 no.6
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• pp.846-855
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• 1999

Background : Secondary pulmonary hypertension is an important final endpoint in patients with chronic hypoxic lung disease, accompanied by deterioration of pulmonary hemodynamics. The clinical diagnosis of pulmonary hypertension and/or cor pulmonale could be difficult, and simple noninvasive evaluation of pulmonary artery pressures has been an relevant clinical challenge for many years. Doppler echocardiography might to be a more reliable method for evaluating pulmonary hemodynamics in such patients in terms of the accuracy, reproducibility and easiness for obtaining an appropriate echocardiographic window than M-mode echocardiography. The aim of this study was to assess echocardiographic parameters associated with pulmonary arterial hypertension, defined by increasing right ventricular systolic pressure(RVSP), calculated from trans-tricuspid gradient in patients with chronic hypoxic lungs. Method : We examined 19 patients with chronic hypoxic lung disease, suspected pulmonary hypertension under the clinical guidelines by two dimensional echocardiography via the left parasternal and subcostal approach in a supine position. Doppler echocardiography measured RVSP from tricuspid regurgitant velocity in continuous wave with 2.5MHz transducer and acceleration time(AT) on right ventricular outflow tract in pulsed wave for the estimation of pulmonary arterial pressure. Results : On echocardiography, moderate to severe degree of pulmonary arterial hypertension was defined as RVSP more than 40mmHg, presenting tricuspid regurgitation. Increased right ventricular endsystolic diameter and shortened AT were noted in the increased RVSP group. Increased RVSP was correlated negatively with the shortening of AT. Other clinical data, including pulmonary functional parameters, arterial blood gas analysis and M mode echocardiographic parameters were not changed significantly with the increased RVSP. Conclusion : These findings suggest that shortened AT on pulsed doppler can be useful when quantifying pulmonary arterial pressure with increased RVSP in patients with chronic lung disease with hypoxemia. Doppler echocardiography in pulmonary hypertension of chronic hypoxic lungs is an useful option, based on noninvasiveness under routine clinical practice.

• Korean Journal of Food Science and Technology
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• v.39 no.2
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• pp.133-137
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• 2007

The 2,2-diphenyl picrylhydrazyl (DPPH) method, which can be used to predict the oxidative stability of edible oils, was previously reported by our research group. Not only free radical scavenging antioxidants but also radicals from oxidized oils are capable of reacting with DPPH radicals, thereby reducing the absorbance of DPPH. In this study, the optimum sample size of edible oils for the DPPH method was determined, and the oxidation of the edible oils was monitored via DPPH, coupled with other conventional methods. The optimum sample size was determined as 1.5 g using soybean oil. Soybean, corn, virgin olive, and refined olive oils were thermally oxidized for 3 hr at $180^{\circ}C$ and analyzed via DPPH, conjugated dienoic acid (CDA) value, and p-anisidine value (p-AV) protocols. Soybean and corn oils were found to be more sensitive to thermal oxidation than virgin and refined olive oils, on the basis of the CDA value and p-AV measurements. The DPPH method can indicate the inherent radical scavenging activity of unoxidized samples, the time required for the depletion of antioxidants, and the rate of degradation of the antioxidants. The soybean and corn oils evidenced higher levels of free radical scavenging compounds, required more time for the consumption of inherent antioxidants, and also manifested steeper antioxidant degradation rates than olive oils, based on the results of DPPH analysis. The DPPH method, accompanied by other conventional methods, may prove useful in predicting the degree of oxidation of vegetable oils.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.74-82
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• 2001

The effects of Al and Mn concentration on dry weight growth, nutrient status and gas exchange rates of 2-Year-old Japanese red pine(Pinus densiflora) seedlings grown in a nutrient culture solution were investigated. Al was added as aluminum chloride at 0, 10, 30 or 60ppm, and Mn was added as manganese chloride at 0, 30 or 60ppm to the nutrient culture solution. The pH of the solution was maintained at 4.0 by adding HCl or NaOH solution. The seedlings were transplanted into the nutrient culture solution, then they were grown in a greenhouse for 90 days. The interactive effects of Al and Mn on the dry weight growth of the seedlings were not significant. There were a main effect of Al or Mn on the dry weight growth and element concentrations of the seedlings. The treatment with Al of ${\geq}10ppm$ or that with Mn of 60ppm induced a significant reduction in the dry weight growth, which indicates that the effect of Al is stronger than that of Mn. The chlorophyll content of needles was not affected by Al treatment, but was significantly reduced by treatment with Mn of 60ppm. Furthermore, the treatment with Al of 60ppm or that with Mn of ${\geq}30ppm$ caused a significant reduction in the dark respiration rate of the roots. The net photosynthetic rate of the seedlings reduced with increasing the concentration of Al or Mn in the nutrient culture solution, which suggests that Al or Mn induced reductions in the relative growth rate(RGR) and net assimilation rate(NAR) of the seedlings were mainly due to the decrease of net photosynthesis.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.539-546
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• 2022

The current ｢Detailed guidelines for the safety and maintenance of facilities (performance Evaluation)｣ prescribes that the durability of surface concrete is evaluated by comparing the measuring the surface rebound value between sound parts and non-sound parts that have surface damage due to winter rain or leakage on concrete. However, this evaluation method was proposed by analyzing the correlation with an experimental DB obtained under freeze-thaw simulation promoting the environment without reviewing on-site applicability. Therefore, this study reviewed on-site application appropriateness of the concrete freeze-thaw damage evaluation method for the 21 concrete bridges in Korea. From the results, it was clearly confirmed that there was a difference in the surface rebound value between the sound part and the non-sound on the concrete surface; the current evaluation method is considered appropriate for application at the site. In addition, the necessity of adding a specific method and a measurement position of surface rebound value were also analyzed, and the effectiveness of the current evaluation method was also analyzed when targeting the entire concrete bridge, not the evaluation of some sections.