• Korean journal of applied entomology
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• v.41 no.1
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• pp.67-73
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• 2002

Studies were conducted to investigate the control effects of several insecticides on Apolygus(=Lygocoris) spinolae(Meyer-Dur) and to develop its management strategies in grapevine yards. Of insecticides which were applied by farmers in commercial grapevine yards, chlorpyrifos, parathion, fenvalerate, and esfenvalerate$.$fenitrothion showed good control effects against A. spinolae. In designed field experiments of fenitrothion and chlorpyrifos for the evaluation of A. spinolae control, both insecticides showed high control efficacy of 94.8 and 91.6%, respectively. The damage of A. spinolae was examined in a grapevine yard, where five different combinations of application timing and number were treated with fenitrothion to assess yield losses (average cluster weight) by A. spinolae. There were no significant differences among average cluster weights of sprayed vines; 466.0 g in sprayed vines on 2 to 3 leaves unfolded stage, 460.7g in sprayed vines on flower separating stage, 465.0 g in sprayed vines each on 2 to 3 leaves unfolded and flowers separating stage, and 487.4 g in sprayed vines each on 2 to 3 leaves unfolded, flowers separating and fruit set stage. Weights of fruit clusters of unsprayed vines was significantly lower than those of sprayed vines. Based on yield and spray cost, chemical control on 2 to 3 leaves unfolded stage produced higher net income than each spray on 2 to 3 leaves unfolded and flower separating stage (i.e., two times of spray), and produced similar net income as each spray on 2 to 3 leaves unfolded, flowers separating and fruit set stage (i.e., three times of spray). Thus, the 2 to 3 leaves unfolded stage was economical spray timing to controlA. spinolae in grapevine yards. Also, management strategies for A. spinolae were discussed.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.4
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• pp.131-141
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• 2014

Over the last decade, the Global Navigation Satellite System (GNSS) has been increasingly utilized as a meteorological research tool. The Korea Astronomy and Space Science Institute (KASI) has also been developing a near real-time GNSS precipitable water vapor (PWV) information management system that can produce a precise PWV for the Korean Peninsula region using GNSS data processing and meteorological measurements. The goal of this paper is to evaluate whether the precise point positioning (PPP) strategy will be used as the new data processing strategy of the GNSS-PWV information management system. For this purpose, quality assessment has been performed by means of a comparative analysis of the troposphere zenith total delay (ZTD) estimates from KASI PPP solutions (KPS), KASI network solutions (KNS), and International GNSS Service (IGS) final troposphere products (IFTP) for ten permanent GNSS stations in the Korean Peninsula. The assessment consists largely of two steps: First, the troposphere ZTD of the KNS are compared to those of the IFTP for only DAEJ and SUWN, in which the IFTP are used as the reference. Second, the KPS are compared to the KNS for all ten GNSS stations. In this step, the KNS are used as a new reference rather than the IFTP, because it was proved in the previous step that the KNS can be a suitable reference. As a result, it was found that the ZTD values from both the KPS and the KNS followed the same overall pattern, with an RMS of 5.36 mm. When the average RMS was converted into an error of GNSS-PWV by considering the typical ratio of zenith wet delay and PWV, the GNSS-PWV error met the requirement for PWV accuracy in this application. Therefore, the PPP strategy can be used as a new data processing strategy in the near real-time GNSS-PWV information management system.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.445-455
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• 2014

The pear sucker (Cacopsylla pyricola) is the most important insect pest in Korea. The hatching rates of overwintered adults laid eggs were observed at 10, 13, 18, and $22^{\circ}C$. The liner model was draw as Y=0.00277X+0.00146(Y=developmental rate, X=temperature) about temperature and developmental rate to eggs. The developmental threshold temperature to eggs was assumed about $-0.83^{\circ}C$. The egg hatching timing over 50% as the accumulated temperature by day maximum temperature $6^{\circ}C$ over from 1st February in 2008, 2009 and 2011 was 429.7, 417.6, and 424.3 degree $^{\circ}C$, respectively, was 3 to 7days before full blooming in pear orchard. On the other hand, the abamectin 1.8EC, lime sulfer, machine oil and 13 kinds of eco-friendly materials were not shown the control effect to the eggs. To mixed stage of pear sucker, the eco-friendly materials over 90% control value were 4 kinds such as a mixture of Azadiractin A+B, Nimbin, Salanin, Meliantriol and Vepol after twice application as 21st May and 5th June in pear growing season, in 2012.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.1
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• pp.79-89
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• 2023

The inventory of many materials requires a large storage space, and the longer the storage period, the higher the potential maintenance cost. When materials are stored on a construction site, there are also concerns about safety due to the reduction of room for movement and working. On the other hand, construction sites that do not store materials have insufficient inventory, making it difficult to respond to demands such as sudden design changes. Ordering materials is then subject to delays and extra costs. Although securing an appropriate amount of inventory is important, in many cases, material management on a construction site depends on the experience of the site manager, so a reasonable material inventory management plan that reflects the construction conditions of a site is required. This study proposes an economical material management method by reflecting variables such as the status of the preceding and following activities, site size, material delivery cost, timing of an order, and quantity of orders. To this end, we set the appropriate inventory amount while adjusting related activities in the activity network, using float time for each activity, the size of the yard, and the order quantity as the main variables, and applied a genetic algorithm to this process to suggest the optimal order timing and order quantity. The material delivery cost derived from the results is set as a fitness index and the efficiency of inventory management was verified through a case application.

• Weed & Turfgrass Science
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• v.3 no.4
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• pp.323-328
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• 2014

This study was conducted to find out the effects of aerial application by unmanned helicopter (AAUH) on controlling weeds under water-seeded rice cultivation. Foliar herbicide (bentazone sodium + fenoxaprop-P-ethyl) was applied with diluted 8-times (standard concentration pest control) as AAUH. Foliar herbicide treatment with standard and two times amount were little damage, but with more than three times amount showed great damage in rice growth. Six annual and two perennial weeds were major weeds occurred in the experimental paddy field. On foliar herbicide treatment 25 days after direct seeding, AAUH showed high control values against weeds (96.3% for annual weeds and 99.8% for perennial weeds). There was no significant difference in weed control values between AAUH and conventional application. There was no spray injury against rice plants with aerial application. In the experiment for good spray timing (15, 20 and 25 days after direct seeding) 15 days showed highest weed control values with 98.5% to annual weeds and 99.8% to perennial weeds and no spray injury.

• Korean journal of applied entomology
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• v.18 no.2 s.39
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• pp.111-116
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• 1979

The experiments were carried out to evaluate the effectiveness of some insecticides in the control of the pine gall midges (Thecodiplosis japonensis Uchida et Inouye) when the low-volume of the insecticides were applied by the mist foliar sprayer. The insecticides, Salithion $(24\%\;Ec)$, Omethoate $(Folimat^{(R)}\;50\%\;Ec)$, Monocrotopos $(Azodrin^{(R)}24\%\;Ec)$, Acephate $(Ortran^{(R)}\;50\%\;Wp)$, Metalkamate $(Bux^{(R)}24\%\;Ec)$. BPMC $(Bassae^{(R)}50\%\;Ec)$ and MIPC $(Mipcin\;50\%\;Wp)$ were tested with 100, 200 and 400 times of water solution on the basis of single application at the six different intervals. Salithion was the most effective for the pressure of the gall formation by the pine gall midges and Omethoate, Monocrotophos and Metalkamate were relativey effective and others no effective. The most reliable concentration of the insecticides was 100 times of water solution, and the feasible timing of insecticide application on the basis of single application would be from May 9 to July 1 with Salithion, June 6 with Metalkamate and June 20 with Omethoate and Monocrotophos. The number of pine needles with the larval injured signs (no larvae in the needles) excluded the gall-formed needles were relatively higher in the treatments of Omethoate, Salithion and Monocrotophos than other insecticides. The treatments of Omethoate, Salithion and Monocrotophos caused the lower larval population in the gall than other insecticides.

• Asian Journal of Turfgrass Science
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• v.21 no.1
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• pp.69-79
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• 2007

Incorporating herbicides application into a fertilization program has several benefits including saving time and reducing traffics on the lawn. Premixed products of fertilizers and herbicides are commonly known as Weed & Feed in the lawn-care industry. To compare Weed & Feed with separate applications of fertilizers and herbicides on a Kentucky bluegrass (Poa pratensis L.) lawn, a Weed & Feed 28-3-3, containing 0.64% 2,4-D, 0.31% MCPP, and 0.03% dicamba of active ingredients, was used in this study. The first application was in May, with the second in June or Sept. Herbicides in forms of 2,4-D (LV-4, 4EC), MCPP (4EC), and dicamba (Clarity, 4EC) were applied at rates equal to the amounts in Weed & Feed or at half of the rates. The dominant weed in both locations was common dandelion (Taraxacum officinale Weber.) in 2005 and 2004. A secondary weed was Canada thistle (Cirsium arvense (L.) Scop.) in 2004 and broadleaf plantain (Plantago major L.) in 2005. When applied in May and June, fertilizer plus full rate of herbicides treatment achieved 112.3 and 83.7 days of acceptable turf quality in 2004 and 2005, respectively. During the same period, Weed & Feed resulted in 58.7 and 24.3 days of acceptable turf quality, respectively. Our study showed that Weed & Feed was generally as effective in weed control as the same amount of fertilizer plus half rates of herbicides sprayed although results may vary due to the timing of application. Fertilizer plus full rates of herbicides provided the same or better results of weed control than Weed & Feed.

• Journal of Korean Dental Science
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• v.8 no.2
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• pp.82-88
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• 2015

Purpose: To evaluate the effect of light-curing on the immediate and delayed micro-shear bond strength (${\mu}SBS$) between yttria-tetragonal zirconia polycrystal (Y-TZP) ceramics and RelyX Ultimate when using Single Bond Universal (SBU). Materials and Methods: Y-TZP ceramic specimens were ground with #600-grit SiC paper. SBU was applied and RelyX Ultimate was mixed and placed on the Y-TZP surface. The specimens were divided into three groups depending on whether light curing was done after adhesive (SBU) and resin cement application: uncured after adhesive and uncured after resin cement application (UU); uncured after adhesive, but light cured after resin cement (UC); and light cured after adhesive and light cured resin cement (CC). The three groups were further divided depending on the timing of ${\mu}SBS$ testing: immediate at 24 hours (UUI, UCI, CCI) and delayed at 4 weeks (UUD, UCD, CCD). ${\mu}SBS$ was statistically analyzed using one-way ANOVA and Student-Newman-Keuls multiple comparison test (P<0.05). The surface of the fractured Y-TZP specimens was analyzed under a scanning electron microscope (SEM). Result: At 24 hours, ${\mu}SBS$ of UUI group ($8.60{\pm}2.06MPa$) was significantly lower than UCI group ($25.71{\pm}4.48MPa$) and CCI group ($29.54{\pm}3.62MPa$) (P<0.05). There was not any significant difference between UCI and CCI group (P>0.05). At 4 weeks, ${\mu}SBS$ of UUD group ($24.43{\pm}2.88MPa$) had significantly increased over time compared to UUI group (P<0.05). The SEM results showed mixed failure in UCI and CCI group, while UUI group showed adhesive failure. Conclusion: Light-curing of universal adhesive before or after application of RelyX Ultimate resin cement significantly improved the immediate ${\mu}SBS$ of resin cement to air-abrasion treated Y-TZP surface. After 4 weeks, the delayed ${\mu}SBS$ of the non-light curing group significantly improved to the level of light-cured groups.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.317-323
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• 2010

This study aimed to examine a suppression effect of salinity on extension rate of stem elongation of cucumber seedlings (Cucumis sativus L.) grafted with roots of figleaf gourd plant. The effects of application methods, timings, and concentrations of two salt types, sodium chloride (NaCl) and calcium chloride ($CaCl_2$), were compared to untreated control plants. In result, an obvious suppression effect on the excessive elongation of stem was obtained by both sub-irrigated and medium-mixed NaCl salt. An improvement in quality of transplants was also obtained by the sub-irrigated NaCl salt. Foliar-applied NaCl caused visible leaf injury when the concentration was higher than 40 mM; but, with no effect on suppressing the stem elongation. When the NaCl was applied at 7 days after grafting, a higher concentration of NaCl was demanded for suppressing the stem elongation compared to an application at the day of grafting. No effect of the NaCl salt on the fresh weights of 36-day grown plants was observed; but, there was a negative effect on the number of female flowers at a high temperature season. Overall, the NaCl salt was more effective on slowing down the stem elongation and had the lower incidence of leaf injury than the $CaCl_2$ salt.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.271-276
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• 2012

A mycoparasite, Paraconiothyrium minitans CM2 was selected for biological control of sclerotinia rot of lettuce caused by Sclerotinia sclerotiorum. The experiment was carried out in a lettuce greenhouse in Yangpyeong from March to April.. When lettuce sclerotinia rot showed in the early stage of occurrence, Conidial suspension of the mycoparasite was weekly treated once to three times onto soil surface around lettuce plants. Incidence of sclerotinia rot in the once-application plot of the mycoparasite ($1{\times}10^7$ spores/$m{\ell}$) and in the benomyl(WP)-treated plot was 11.0% and 2.7%, respectively, whereas that of control was 31.0%. Incidence of twice- and three-application plots of the isolate was 7.9% and 12.8%, respectively. For increasing the effect of the mycoparasite, the experiment for the timing of application of P. minitans CM2 was carried out in a lettuce greenhouse in Yangpyeong and Suwon. Control efficacy against lettuce sclerotinia rot in the soil-drenching plots of P. minitans CM2 ($5{\times}10^6$ spores/$m{\ell}$) in the planting was 75.3~84.7%, and control effect by treatment of the isolate at the pot drenching+the soil-drenching plots in the early stage of disease occurrence was 63.8~58.0%. As the results, P. minitans CM2 could be a prospective biofungicide for biological control of sclerotinia rot of lettuce.