• Korean journal of applied entomology
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• v.58 no.4
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• pp.321-327
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• 2019

When Aphidius colemani mummies were stored at four different temperatures (6, 8, 10 and 12 ± 1℃), they could be stored at 8℃ for 10 days with over 50% adult emergence. A number of mummies of Rhopalosiphum padi parasitized by A. colemani adults emerged from mummies after 8℃ storage clearly reduced with increasing duration of storage and especially declined with storage longer than 13 days showing < 20% parasitism. However, there were no differences in aphid parasitisms by A. colemani on 3 to 10 days after storage. Over 3 day storage at 8℃ was adversely affected on survival of A. colemani adults. Therefore, cold storage of A. colemani adults is considered as an unsuitable method for mass production of biological control agent. When 2-day-old Meteorus pulchricornis cocoons were stored at 6, 8 and 10 ± 1℃, it was possible to be stored up to 63 days at 8℃, showing the highest emergence. With increasing of cold storage duration at 8℃, parasitism on 2^nd and 3^rd larval instar of Spodoptera litura by stored M. pulchricornis significantly reduced. However, parasitic rate by M. pulchricornis stored for 2 weeks was similar to that by 1 week stored ones. Therefore, M. pulchricornis cocoons could be stored up to 2 weeks at 8℃ for stockpiling before release.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.75-86
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• 2008

Many kinds of environment friendly agricultural materials (EFAMs) were used for the plant protection, furthermore they support the growth of crops in the greenhouses and the kindly environment friendly farming. Natural enemies might be used for control of insect pest with EFAMs at the same space and time. For testing the toxicity of EFAMs against to natural enemies, 10 EFAMs were selected and tested in small greenhouses and farm's fields. In case of Harmonia axyridis larva, there was no predacious activity against cotton aphids in the block with EFAMMo L, EFAMPE D, EFAMME G and EFAMAE A, otherwise, aphid population was rapidly decreased in the control block without EFAMs. Both of Trialeurodes vaporariorum and Encarsia formosa population were slightly decreased in the block with EFAMs. There were significantly decreased in the block with IEFAM C, FEFAM D, EFAMSM Band EFAMPE D compared with control area. Especially, there was significantly maintained a very low population, both T. vaporariorum and E. formosa in the block with EFAMMo C. The parasitized ratio of Aphidius colemani is also very low in the block with EFAMs compared with control area. In the block with IEFAM C, FEFAM D, EFAMPE D and EFAMMo L, there were significantly different with control area in the number of mummies. Otherwise, in case of Diglyphus isaea and Liriomyza trifolii, there was no significantly different between blocks with and without EFAMs. In the block with EFAMMo C, Tetranychus urticae and Phytoseiulus persimilis populations were significantly maintained a very low level. However, the population of T. urticae was increased, but P. persimilis was decreased in the block with EFAMMo L.

• Parasites, Hosts and Diseases
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• v.21 no.1
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• pp.105-110
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• 1983

A survey on vegetables, which consisted of lettuce (Lactuca sativa) , young radish (Raphanus sapiwus), and chinese cabbage (Brassica pekinensis) collected from 6 markets in the Taegu city, was conducted for the discovery of helminth eggs and larvae, from July, 1982 to June, 1983. The results were compared with the data obtained from vegetables collected at the same markets by Lee (1969) and Choi and Lee (1972). Both sides of vegetable leaves were washed carefully with a hard brush, and the species of parasites and the mean number of parasites per 200g of vegetable were determined. When vegetable were examined, 4 species of parasite eggs (ascarid, Trichostrongylus, liver fluke, and hookworms) and 2 larvae (filariform and rhabditoid larvae) were found. Of the parasite discovered, ascarid egg was found to be highest (4.2%) , followed by hookworm egg (3.6%) . The mean number of ascarid egg per 200 grams of vegetable was 0.6 in young radishes, and 0.3 in both lettuces and and chinese cabbages. Similarly, the number of filariform larva of hookworm was 0.4 in young radishes, 0.3 in lettuces, and 0.1 in chinese cabbages, and the number of rhabditoid larva was 0.2 in young radishes, 0.1 in lettuces, and 0.05 in chinese cabbages. In the results obtained by Lee (1969) and Choi and Lee (1972) , the mean number of ascarid egg per 200 grams of vegetable was 7.5 in young radishes, 3.1 in lettuces, and 0.5 in chinese cabbages. By contrast, in the present study it was 0.6 in young radishes an 0.3 in both lettuces and chinese cabbages. These results suggest that there has been significant reduction in the incidence of parasite egg and larva on vegetable leaves during the past 10 years.

• Journal of fish pathology
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• v.10 no.1
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• pp.21-29
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• 1997

We investigated on the prevalence and extermination of scuticociliatids parasitic on cultured japanese flounder, Paralichthys olivaceus in land-marine tank system of southern Korea from January to February in 1997. The gills and the skin showed the highest infection rate(60%), and the brain showed the lowest(22%). Also, fish secreted large quantity of mucus with a bleeding and ulcerated lesions on the infected sites. The number of the parasites in inflowing sea water, surface water and bottom water of farming tank ranged 0~1 individuals/$100m\ell$, 0~413 individuals/$100m\ell$ and $7\sim7.3{\times}10^4$ individuals/$100m\ell$, respectively. This parasite was died within 2 hours in 50~500 ppm, 48 hours of 10 ppm formalin or hydrogen peroxide, 1 hour in 50~500 ppm, 80 minutes of 10 ppm oligo chitosan and 10 minute in 100% but did not died until 48 hours in 10~70% fresh water.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.2
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• pp.202-208
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• 2003

In this paper, we proposed a microstrip patch array antenna for DBS reception which had high gain and high tilted angle through mutual coupling driver patch to parasitic patch in H-plane edge and broadside direction in different layers. It was designed and fabricated in 16$\times$8 array by using low cost polyester based copper-clad laminate and foam instead of high cost dielectric substrate. It had gain of 22.9 dBi, beamwidth of 4.6$^{\circ}$, and tilted angle from broadside direction of 43.9$^{\circ}$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.6
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• pp.83-88
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• 2003

This paper analyses a fault operation due to the effect of miller capacitance, which severely influences the performance of the IPMs based on computer-aided simulations, and also it presents a good solution to solve that problem. A miller capacitance existed between gate and collect is very closely related to the stray capacitance formed between gate and emitter, and the value of gate resistor. These relationships are proved by the computer-aided simulation. Based on the PSpice simulation results, a customized IPM employing an auxiliary circuit is presented to minimize a fault operation. And it is compared to the standard IPM by the experimental waveform. As a result, it is verified that a customized IPM has a voltage margin to prevent a fault operation approx. 3 [V].

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.3
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• pp.68-73
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• 2011

In this paper, a compact-narrow open stub band-pass filter with parasitic-signal of low frequency range and second harmonics rejected using the parallel coupled line and FLCLM(Frquency Locked Controlled Length Method) is proposed. The characteristic of the parallel coupled line can be rejection for parasitic-signal of low frequency range and second harmonics. In last filter of experimental results show that insertion loss is 1.2 dB and return loss is 14.8 dB, and the fractional bandwidth is 10 % at the center frequency of 5.8 GHz. In additional, the rejection for parasitic-signal of low frequency range and second harmonics are 28.9 dB and 28.8 dB, respectively.

• Journal of fish pathology
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• v.24 no.2
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• pp.167-171
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• 2011

On September in 2010, myxosporidian parasites were found on the fins of Chinese muddy loach, Misgurnus mizolepis, Several cysts of approximately 2 mm diameter were observed on the fins. Numerous spores were found in the cyst. The total length of the spore was 13.0 to 15.8 ${\mu}m$, and the width of spore was 6.0 to 7.5 ${\mu}m$. As the results, the myxosporidians were finally identified as Thelohanellus misgurni (Kudo, 1919) on the basis of the presence of characteristic cysts and size of spores.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.10
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• pp.34-43
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• 1990

An improved parameter adaptation and control law for robot manipulator are proposed based on a linearized parametric system equation and augmented error vectors. In view of the modeling error and parasitics with small time constants which inevitably introduced during modelling process, their effects on the robustness of the system performance are reviewed and as an conutermearsure, adaptation mechanism with low pass filter is proposed. Proposed parameter adaptation and control low assure the stability of the robot manipulator in the large without further assumption. Computer simulation shows its effectiveness of the proposed adaptation mechanism to improve the robustness of the system in presence of the parasitics in the system and superior performance for high speed operations make it an attractive option in application of the adaptive control field for robot manipulator.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.241-259
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• 2006

Polydnavirus is a mutualistic DNA virus found in some braconid and ichneumonid wasps. Its genome is integrated into host chromosome as a provirus. Its replication occurs at ovarian calyx epithelium during host pupal stage to form episomal viral particles. The viral particles are delivered into hemocoel of the parasitized insect along with eggs during wasp oviposition. Several polydnaviral genomes, which are isolated from the episomal virus particles, have been sequenced and exhibit some gene families with speculative physiological functions. This review presents the viral characteristics in terms of Its parasitic physiology. For developing new insect pest control tactics, it also discusses several application strategies exploiting the viral genome to manipulate insect physiology.