• Korean journal of applied entomology
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• v.29 no.4
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• pp.269-276
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• 1990

This study investigated host range, seasonal occurrence and developmental characteristics of Ceroplastes pseudoceriferus Green on persimmon trees. The host plants covered 34 families and 66 species, including newly recorded species of Chenopodum album var. centrorubrum, Glycine max, Begonia semperflorens, Pharbitis nil, Perilla frutescens var. japonica and Erigeron canadensis. There was one generation of C. pseudoceriferus a year with larval stage expanding from mid-June to mid-October. Average number of eggs laid per female was 1,073$\pm$177.3. Hatching rate was 97.3% and was not affected by temperatures and photoperiods. Stadium varied as 23.4 days in eggs, 128.3 days in larvae and 213.3 days in female adults including overwintering periods at natural condition.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.3 s.357
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• pp.78-84
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• 2007

A multistandard direct-conversion mixer for WCDMA, Wibro, and 802.11a/b/g is designed in 0.18 um CMOS technology To support multistandard and to reduce the chip area the switched inductor is used as the matching method. This switched inductor matching network selects the mixer's operation frequency band by turning on or off the switch transistor. Since the performances of mixer and operation frequency can be affected by the parasitic of switch transistor the mixer should be designed with the optimized size of switch to minimize parasitic effects. Proposed mixer is able to achieve return loss less than -13 dB in $2.1\sim2.5GHz$ and $5.1\sim5.9GHz$ bands with the suitable performance to meet requirements of WCDMA, WiBro, and 802.11a/b/g.

• Parasites, Hosts and Diseases
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• v.26 no.1
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• pp.9-14
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• 1988

In an attempt to determine the susceptibility of inbred golden hamsters(Mesocricetus auratus) to the experimental infection with Clonorchis sinensis, twenty-five hamsters were divided into 5 groups and administered orally 5, 10, 20, 30 or 50 metacercariae each. The hamsters were killed on the 45th day after infection. The adult flukes were recovered from all hamsters. The overall recovery rate for the fluke was 57.9% with the range of 48.4% to 92.0%. As the number of the metacercariae given increased, a porportionate decrease in the recovery rate was found, the prepatent period of the fluke in the hamster varied from 15 to 17 days, with the average of 16 days. No significant differences in the development of the flukes were observed. Egg production expressed by EPG, increased step by step as the time elapsed. However, a tendency of decreasing egg laying capacity was observed with the increase of worm burden. It is suggested that the hamster is a suitable final host of C. sinensis.

• Korean journal of applied entomology
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• v.34 no.3
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• pp.229-233
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• 1995

The life history, seasonal occurrence of larval population and natural enemies of Tea leaf roller (Caloptilia theivora (Walshingham) were investigated in field-age. C. theivora had 6 generations a year. The developmental periods from egg to adult emergence were 32.1~38.6 days in spring and fall, and 24.8~32.7 days in summer. The average longevities of adults were 8.4~14.5 days in spring and fall, and 6.3~8.6 days in summer. The average number of eggs laid by a female were 55~71 throughout the season. Larval population density of C. theivora showed 3~4 peaks from middle may in 1992 and 1993. However, population density of 194 was pretty low in early season and exhibited a peak in late September-early October. C. theivora overwintered in pupal stage on the leaves. Four hymenopterous parasitoids of C. theivora larvae were identified ; they are Stenomesius japonicus (Ashmead), Sympiesis ringoniellae Kamijo, Elasmus sp., and S. dolichogaster Ashmead which is dominant.

• Korean journal of applied entomology
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• v.19 no.4 s.45
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• pp.187-192
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• 1980

This study was carried out to investigate the bionomics of Ostrinia furnacalis $(Gu\grave{e}n\grave{e}e)$ in the laboratory and field in 1978. The oriental corn borer had three generations a year in Korea ana the first period of moth activity was mostly from early June to early July, the second from mid July to mid August and the third from mid August to early September. It overwintered with larval stage in the corn stubbles. The egg period was 3-4 days. The larva molted 5-6 times and its period was 18-30 days. The longevity of adult was 7-11 days and deposited about 600-800 eggs. An egg parasite and two larval parasites were investigated.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.3
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• pp.15-20
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• 2004

In this paper, a wideband two-layer H-shaped microstrip antenna for WLAN is designed. To increase the bandwidth of microstrip patch antenna a configuration of stacked type using parastic element is used. Furthermore, to reduce the size of microstrip patch antenna, two techniques are employed . the first one is H-shaped patch type and the second one is that the main radiator and parastic patch are shorted to the ground plane using ten shorting posts. The antenna bandwidth and radiation characteristics are calculated by ENSEMBLE ver. 5.0 simulation software, and compared with the experimental results. Experiment results show that the bandwidth of antenna in 740MHz centered at 5.46㎓(13.5%), which is close agreement with the calculations, 770MHz(13%). Also, the antenna size can be reduced by 71.5% compared with the half wavelength rectangular microstrip antenna using the same substrate at the same frequency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.7
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• pp.737-746
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• 2014

Recently, researches about MIMO(Multi-Input Multi-Output) system are being studied actively due to high-capacity and high-speed communication. However, MIMO system has many RF(Radio Frequency) chains according to many array antennas. So, MIMO system has disadvantages such as high-complexity and high-power-consumption. Also, it is impossible to miniaturize the antenna dimension. In order to solve these problems, beamspace MIMO system using ESPAR(Electronically Steerable Parasitic Array Radiator) antenna was proposed. It is possible to reduce the complexity and the power-consumption, because it has single RF chain by using one active antenna and several parasitic elements. In this paper, in order to improve the security, for the first time, chaos communication algorithm is applied to QPSK modulated beamspace MIMO system using ESPAR antenna. We define as chaos QPSK beamspace MIMO system, and evaluate the SER performance. Also, we confirm that QPSK symbols can be made by changing the reactance values of parasitic elements, and evaluate the SER performance of this system.

• Parasites, Hosts and Diseases
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• v.31 no.1
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• pp.1-6
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• 1993

Among taenited tapeworms inferting humans though pork or beef, Taenia solium Linnaeus 1758 and Taenia sagina Goeze 1782 have already been. Based on the morphologic characteristics of adult and metacestodes of Asian Taenia saginata, the third kind of human taeniid tapeworm konwn to disdute in Asian counteries, a new spscies name of Taenia asiatica is proposed. In addition to the known biology in their intermediate hosts, T.asiatica was diffierent morphologically from Taenia saginata Goeze 1782 in having the unarmed rostellum on the scolex of adlut, the large number of 'unterinetwigs' and the existence of 'posterior protuberance'. These structures in the gravid proglottids were used as taxonmic keys in taeniid tapeworms for the first time. T. asiatica metacestode (Cysticercus viscerotropica)was different morphologically from T. saginata metacestode (Cysticercus bovis) in having wartlike formations on external surface of the bladder wall.

• Journal of Navigation and Port Research
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• v.34 no.3
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• pp.167-173
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• 2010

In order to design small printed antenna restricted within narrow area of $30mm{\times}8mm$ for the Zigbee module and improve its return loss, meander slot antenna with a floating conductor as the parastic element has been proposed. The resonant frequency and bandwidth(VSWR${\leq}$2) of the antenna designed and fabricated in the present study is about 2.44GHz and 113MHz respectively. The radiation pattern is almost similar to that of dipole antenna within the operation frequency range. Also the radiation efficiency and gain of the proposed antenna is more than 60% and 2.7dBi respectively. It has been observed that the characteristics the proposed antenna mentioned above satisfy the specification required of the Zigbee application. In order to validate the proposed antenna, some simulated and measured results are presented and compared.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.2
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• pp.40-50
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• 2010

The studies of PMOS transistors in CMOS technologies are reviewed- focusing on the snapback and breakdown behavior of the parasitic PNP BJTs in high current regime. A new failure mechanism of PMOSFET devices under ESD conditions is also analyzed by investigating various I/O structures in a $0.13\;{\mu}m$ CMOS technology. Localized turn-on of the parasitic PNP transistor can be caused by localized charge injection from the adjacent diodes into the body of the PMOSFET, significantly degrading the ESD robustness of PMOSFETs. Based on 2-D device simulations the critical layout parameters affecting this problem are identified. Design guidelines for avoiding this new PMOSFET failure mode are also suggested.