• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.327-331
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• 2011

Purpose: The purpose of this study was an accurate grasp of the astigmatic change due to eyes accommodation on near vision and suggested problems occurring accommodative astigmatism using near glasses. Methods: 154 subjects(308eyes) from 20 to 40 years selected for this study who had many opportunity of near vision. First, far vision corrective refraction measured using the phoropter, and then both eyes opened simultaneously for maintaining the function of binocular put away dot chart 40 cm. One eye was fogging and the other eye measured near vision astigmatism axis and degrees astigmatism using cross cylinder, and then compared with far astigmatism. Results: Increased degree of astigmatism persons on near vision more than decreased or did not changed degree of astigmatism persons, which could affect visual acuity more than 0.75 diopters in 30 eyes with an increase of 9.7% of total subjects. Direct astigmatism and oblique astigmatism were increased on near vision. Astigmatic axes were rotated base in direction on both eyes and 66.9% of subjects were more than ${\pm}$5$^{\circ}$ rotation. Due to the rotation axis of astigmatism, residual astigmatism is expected to occur and expect to adversely affect the eyes. Conclusions: Long-term using the glasses without correction of increased astigmatic and rotated axis on near vision should occur new residual astigmatism and increase the asthenopia also. Considered to be taken astigmatic change on near vision during near refraction examination.

• Journal of the Korea Institute of Building Construction
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• v.19 no.1
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• pp.9-18
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• 2019

Concrete, which is the most widely used building material in modern times, has been improved not only in strength but also in structural performance such as increase in toughness and ductility, weight reduction, and improvement in quality of human life. Due to the surge in demand for the building, there is a tendency to be used variously from architectural panel and architecture to interior accessories. In Korea, a light-transmitting concrete, LEFC(Light Emotion Friendly Concrete), that insert plastic rods to stimulate emotional sensation through the combination of light and concrete has developed. In previous research, it was confirmed that the use of a synthetic foam agent rather than an animal foam agent did not cause a fogging phenomenon. In this study, lightweight by applying foaming agent to LEFC and two types of fiber (Nylon Fiber, Polyvinyl Alcohol) were compared to achieve to investigate the fiber to be applied in future. An equation that can predict the loss and adhesion reduction of the concrete section according to the diameter of the rod (5mm, 10mm) and the interval (10mm, 15mm, 20mm) was proposed.

• Parasites, Hosts and Diseases
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• v.22 no.1
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• pp.102-108
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• 1984

This paper is the result of adult female mosquito and larval collection in U.S. Army Installations in Korea from 1979 to 1983. New Jersey light traps were operated for adult collection from May to October. The primary concern of this surveillance is to determine when to recommend insecticide spraying for mosquito control in the Army areas. The 5th Preventive Medicine Unit have developed an "index" level of female mosquitoes in a light trap similar to other U.S. Army Agencies in other parts of the world. When 10 female mosquitoes are reached on two consecutive trap-night, or 5 known vector females are collected, fogging is recommended in the trap areas. 1. Mosquito collections were conducted in 12 U.S. Army areas by operating 39 New Jersey light traps. Mosquitoes collected from the areas were identified to be 17 species comprising 3 genera. Anopheles sinensis (40%), Culex tritaeniorhynchus (31%), Aedes vexans nipponii (19 %) and Culex pipiens pallens (10%) appeared to be the most common species in the areas. 2. The species, population density and monthly appearance of adult mosquitoes were found to be almost the same in the all provinces involved. And Japanese Encephalitis vector mosquitoes, Culex tritaeniorhynchus, showed their seasonal fluctuation from July to September with a peak in August each year. 3. Larval habitats confirmed in the Army areas were categorized into 16 types as shown in Table 3. The mosquito larvae collected in those habitats were identified to be 15 species representing 4 genera. Most breeding sites in the Army areas were those which are activated during the wet season. 4. More mosquitoes were collected from the Kyungki Province than from the other Provinces. The reason for more collection of mosquitoes from military installations in the Kyungki Province appears to be the geographic characteristics surrounded by rice fields, marshes and other stagnant water areas.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.114-119
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• 2012

We have conducted 4 experiments to develop the most environmental and effective use of the two-fluid fog system to prevent and exterminate whiteflies in tomato cultivation. In particular, these experiments used Vitamini tomatoes grown in stand-alone greenhouses at Buyeo Tomato Experiment Station as subjects. Each experiment utilized the fog system in a different way. The first experiment provided the control group, which was subject to the two-fluid fog system without additional humidity control. In the second experiment, the two-fluid fog system controlled the humidity level to be above 70%. The third and the fourth experiment utilized natural substances, which were 1.5 mg/L of Neem Oil and 2 mg/L of Oleic acid respectively, without additional humidity control. From the first experiment, we could observe that a simple use of the two-fluid fog system decreased the density of whiteflies in the greenhouses. This impact of the fog system on whiteflies was greater in the second experiment. By comparing the first and the second experiment, we concluded that whiteflies are more effectively prevented by maintaining a higher humidity level via the fog system's smaller water droplets that float in the air for longer time than the standard fog system in rather dry condition. In the third and the fourth experiments, the extermination level was 78% and 76.4% respectively, comparing only 53% in the first experiment without the humidity control. Therefore, using the natural substances in addition to the humidity control increases the extermination effectiveness. Considering the similar results from the 3rd and the 4th experiments, Oleic acid has a greater appeal for its lower price. Using the two-fluid fog system to both control the humidity on a daily basis and spray the substances for occasional extermination would reduce labor cost and increase production in an environmental way.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.429-437
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• 2019

This study was conducted to examine the effect of humidification and shading during cutting propagation on growth and development of strawberry (Fragaria x ananassa Duch.) 'Maehyang' plants at a propagation stage. The runner cuttings were stuck on Nov. 23, 2017 in propagation benches set in a Venlo-type glasshouse. Four shading treatments, no shading (control, C), 55% shading with white lawn (W55), 55% black shading net (B55), or 100% black plastic film (B100) with either an intermittent fog system (H) or without fog system. The shading and fog systems were removed 2 weeks after sticking of strawberry cuttings. A nutrient solution for strawberry, which was developed by Yamazaki, was supplied once a day with electrical conductivity (EC) $1.6dS{\cdot}m^{-1}$ and pH 5.8. Growth parameters such as plant height, longest root, crown diameter, leaf chlorophyll, leaf area and fresh and dry weight were measured at 7 days and 26 days after sticking. There was no significant difference in growth of above-aerial part of strawberry. The overall growth of the strawberry roots was better grew by providing fog than that not provide fog. The root fresh weight and root dry weight after 26 days after sticking of strawberry cutting was the best in the treatment that provided fog system without shading (CH). The longest root after 26 days after sticking of strawberry cutting was the best in the treatments that provided fog system with either 55% white lawn (W55H) and 55% black shading net (B55H). These results suggest that morphogenesis of these plants were affected by humidification and shading types. In a broader perspective, these results can be used to optimize studies of other crops grown from cuttings.