• Journal of Veterinary Clinics
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• v.26 no.6
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• pp.586-590
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• 2009

Horsehair worms (Chordodes koreensis) develop as parasites in the bodies of grasshoppers, crickets, cockroaches, and some beetles. Chordodes koreensis is an accidental parasite of humans, livestock, or pets and poses no public health threat. The male of Chordodes koreensis in the later larval stage from canine vomitus was investigated by the scanning and transmission electron microscopy. In cross sections, the body wall is composed of four components namely epicuticle, cuticle, epidermis, and muscle layers. The parenchymal tissue fills the rest of the body and surrounds the visceral organs such as intestine, and ventral nerve cord but testes were not found. The epicuticle is a thin superficial layer whose surface shows rows of polygonal elevations called areoles. The cuticle has 17 layers of collagenous fibers spirally wound about the long axis of the worm. The section through the cuticle reveals the layers of large fibers cut obliquely lengthwise, alternating with layers of fibers sectioned obliquely crosswise. The layers of large fiber formed a double helix about longitudinal axis of the worm. The epidermis is a single layer. The muscles were interrupted by the nervous lamella in the only midventral portion. The medulla of muscle plate is composed of lightly stained cytoplasm, mitochondria, weakly developed endoplasmic reticulum, and glycogen granules. Between the medulla of a cell and the plasmalemma lies a broad cortical zone of myofilaments. The circular muscles are absent. The characteristic feature of the cytoplasm is that there was no content in peripheral mesenchyme, but was an abundance of large clear vacuoles which give the cytosome a foamy appearance. The nucleus of mesenchyme is not easily identified in our specimens.

• Korean Journal of Agricultural Science
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• v.4 no.1
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• pp.66-74
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• 1977

To investigate the condition of infectious rate of fascioliasis in the farm animals. This survey was carried out, by the interdermal reaction from different animals, ages and pestures in Daejeon Suburbs and Cattle market and Abattoir. The average positive rate of infectious reaction were 31.0% in Korean Cattle, 38,7% in dairy Cattle, 33.8% in Korea native Goats and 26.9% in dairy Goat. The positive rate was higher at the age of 2~6 that compares with at age of yearling. From survey on the river side area, valley and wet area, the rate of positive was occured higher, than from plain, high land and in case of animals have not been grazing. And the detective rate of liver fluke among the positive reaction was occured 92.5% in Korean Cattle and 94.7% in Korea native Goat.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.12
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• pp.1059-1068
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• 2016

This paper proposes slow wave structure(SWS) utilized to increase antenna gain of printed dipole antenna(PDA) and to suppress sidelobe level simultaneously, and makes sure of electrical characteristics of the antenna according to parameter variations of components of the slow wave structure. The printed slow wave structure which is composed of a dielectric substrate and a metal rods array is located on excited direction of the PDA, affecting the radiation pattern and its intensity. Parasitic elements of the metal rods are arrayed in narrow consistent gap and have a tendency to gradually decrease in length. In this paper, array interval, element length, and taper angle are selected as the parameter of the parasitic element that effects radiation characteristics. Magnitude and phase distribution of the electrical field are observed and analyzed for each parameter variations. On the basis of these results, while the radiation pattern is analyzed, array methods of parasitic elements of the SWS for high gain characteristics are provided. The proposed antenna is designed to be operated at the Wifi band(5.15~5.85 GHz), and parameters of the parasitic element are optimized to maximize antenna gain and suppress sidelobe. Simulated and measured results of the fabricated antenna show that it has wide bandwidth, high efficiency, high gain, and low sidelobe level.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.423-432
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• 2022

The mass-rearing system for Neodryinus typhlocybae as a biological control agent of Metcalfa pruinosa was established. Depending on the density of host nymphs and plants, the average number of cocoons produced by the parasitoids was 5-8 and 70-150 cocoons per leaf and sapling of mulberry, respectively. There is a significant difference in cocoon length between females (6.10-6.46mm) and males (4.20-4.62mm). Sex determination of cocoons before emergence will be helpful for efficiently releasing this parasitoid in fields. The parasitic rate of N. typhlocybae at the semi-field condition was on average 13-17%. The release number of this parasitoid did not affect parasitism. Nevertheless, the population growth rate of M. pruinosa was reduced by increasing the release number of N. typhlocybae. The parasitoid offspring's sex and bivoltine were influenced by the host age. On young host nymphs, the bivoltine portion of parasitoid increased. When parasitized on 4^th or 5^th nymphs, the offspring's female ratio of N. typhlocybae increased. This result may be useful for potentially controlling mass rearing production of parasitoid.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.1
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• pp.8-18
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• 2000

We presented a BGA(Ball Grid Array) package for RF circuit modules and extracted its electrical parameters. As the frequency of RF system devices increases, the effect of its electrical parasitics in the wireless communication system requires new structure of RF circuit modules because of its needs to be considered of electrical performance for minimization and module mobility. RF circuit modules with BGA packages can provide some advantages such as minimization, shorter circuit routing, and noise improvement by reducing electrical noise affected to analog and digital mixed circuits, etc. We constructed a BGA package of ITS(Intelligent Transportation System) RF module and measured electrical parameters with a TDR(Time Domain Reflectometry) equipment and compared its electrical parasitic parameters with PCB RF circuits. With a BGA substrate of 3${\times}$3 input and output terminals, we have found that self capacitance of BGA solder ball is 68.6fF, and self inductance 146pH, whose values were reduced to 34% and 47% of the value of QFP package structure. S11 parameter measurement with a HP4396B Network Analyzer showed the resonance frequency of 1.55GHz and the loss of 0.26dB. Routing length of the substrate was reduced to 39.8mm. Thus, we may improve electrical performance when we use BGA package structures in the design of RF circuit modules.

• Parasites, Hosts and Diseases
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• v.36 no.3
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• pp.171-182
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• 1998

A total of nine Korean native kids and two Corriedale lambs, 1-20 days old, were each inoculated per os with a single dose of 2 × 107 oocysts of Cwptospori,mum muris (strain MCR) originated from mice to elucidate the kinetics and developmental stages of the coccidium in small ruminants. Irrespective of host's age, the prepatent period for both animals ranged from 19 to 35 days (28.1 days, on the average) and the patent period 16-85 days (47.8 days), and the total oocyst outputs showed enormous differences. Infection with greater numbers of oocyst outputs was not ordinarily established by transmission experiments. Oocysts discharged from the kids retained their infectivity by the mouse titration method. The immunogenicity of the coccidium and oocyst reproduction were proven by challenge infection and administration of prednisolone acetate. respectively. All the developmental stages of the coccidium in parasitophorous vacuoles were found by transmission electron microscopy in the pits of the gastric glands of a kid inoculated with oocysts and then necropsied on day 44 postinoculation. It indicated the full course of the host-parasite relationship in kids and lambs as well as mice.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.48-49
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• 2015

본 논문에서는 3상용 6팩 인버터 모듈을 이용한 가극성 커플드 인덕터를 갖는 영전압 스위칭 펄스-폭변조 단상 풀-브릿지 인버터를 제안한다. 모듈을 이용하기 때문에 시스템의 조밀한 설계가 가능하여 영전압 스위칭 구현에 있어 큰 영향을 미칠 수 있는 기생 성분들을 줄이는데 용이할 수 있다. 본 논문에서 제안된 회로의 동작 원리와 특성들을 다룰 것이며 시뮬레이션을 통하여 가능성을 검증하였다.

• Parasites, Hosts and Diseases
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• v.28 no.1
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• pp.63-67
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• 1990

This study was performed to evaluate the status of intestinal parasitic infections among the inhabitants in two islands (Chu-do and Doomi-do) of Tongyeong.gun, Kyeongsangnam-do (Province), from August to September, 1989. A total of 189 stool specimens was collected from the inhabitants of 3 villages and examined by Kato's cellophane thick smear and formalin.ether sedimentation techniques. Stoll's dilution egg counting technique was done for the quantitative examination of helminth eggs. The overall Positive rate of intestinal Parasites was 30.2%. The egg Positive rate of Ascaris lumbricoides was 2.1%, that of Trichuris trichiura 24.3%, hookworm 2.1%, Trichostrongylus orientazis 0.5%, Czonorchis sinensis 1.1%, heterophyid 1.6%, and Taenia species 2.6%. The cyst positive rate of Giardia lamblia was 1.6% and that of Entamoeba soli 0.5%. In T. trichiura infection, the egg Positive rate of females (29.9%) was much higher than that of males (17.2%). Among the age groups, 10~19 year group showed the highest inflection rate, 32.4%. It was revealed that the prevalence of intestinal parasitic infections among the inhabitants of remote islands should be still high in comparison with ever-reported ones in urban or rural areas.

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.41-46
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• 1983

Nine species of plant parasitic nematodes, Aphelenchoides besseyi, Aphelenchus avenae, Criconemoides informis, Helicotylenchus dihystera, Meloidogyne arenaria, Meloidogyne hapla, Pratylenchus minyus and Tylenchus sp. Were found in peanut field in Korea. Chemicals used were; Telon C-17, Mocap 10G and Carbofuran 3G for control peanut parasitic nematodes. All chemicals reduced nematode populations but varied in effectiveness. Telon C-17 was especially effective against Meloidogyne hapla, the principal species on peanut and resulted in significant yield increased than the control. Plant height, number of branches and dry weight of peanut were increased over the nontreated control by chemical soil treatments.

• Korean journal of applied entomology
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• v.15 no.3 s.28
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• pp.133-136
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• 1976

In order to survey the kinds and distribution of tobacco parasitic nematodes, 51 soil samples were. collected from 14 associations under the office of Monopoly of Kyungbuk and Kyungnam province. 1, The plant parasitic nematodes were found $96.1\%$ in the whole sampled. 2. The propotion of infested field of each nematode genera, Tylenchus shown as dominant by $82.3\%$ and next Aphelenchus $72.5\%$, Tylenchorhynchus $58.8\%$, Meloidogyne$50.9\%$, Criconemoides $25.4\%$, Pratylenchus, Hirschmanniella $23.5\%$ in order. 3. The density of genera per localities were as follows Pratylenchus is most abundant in Youngdeog as 43 population, Tylenchorhynchus shown in Jinbo, Tylenhus in Yeongil, Meloidogyne in Kimcheon, Xiphinema in Euisung. 4. Eighteen species belonging to 16 different genera of 11 families were identified, 12 of them are new for Korea as tobacco parasitic nematodes; Aglenchus costatus, Aphelenchus avenae, Criconemoides informis, Ditylenchus dipsaci, Helicotylenchus dihystera Hirschmanniella imamuri, Meloidogyne incognita, Psilenchus hilarulus, Rotylenchus pini, Tylenchorhynchus claytoni, Tylenchorhynchus nudus and Xiphinema americanum.