• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.141-150
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• 1991

A local isolate of chicken anemia agent (CAA), isolate 89-69. was tested for pathogenicity for chickens. When chickens from a specific pathogen free (SPF) flock were inoculated intramuscularly with the isolate at one day old, all the chickens showed severe anemia at 14 to 18 days post inoculation(DPI) and returned to normal at 25DPI, Some of the inoculated chickens (27∼33％) died between 13 to 17 DPI's with lesions of severe aplasia of bone marrow and thymic atrophy. In chickens kept in contact with inoculated chickens, some of the chickens had anemia at 25 and 28 DPI's. Virus could be reisolated from inoculated as well as in contact chickens till 21 DPI. Antibodies to CAA could be detected in all inoculated and in contact chickens when tested at 42 DPI by the indirect fluorescent antibody method. When chickens from a different SPF flock were inoculated at one day old, degrees of anemia, both in frequency of incidence and severity, were low These chickens were proved partly to have antibodies to CAA when tested for hatchmates. In a survey for antibodies to CAA in field chicken flocks, one out of 7 flocks(14％) aged 3 to 10weeks was antibody positive whereas 19 out of 20 flocks(95％) over 20 weeks of age were positive. Altogether 29 out of 39 flocks (74％) were antibody positive.

• Journal of fish pathology
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• v.35 no.2
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• pp.167-176
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• 2022

We injected infectious myonecrosis virus (IMNV) to pacific whiteleg shrimp, Litopenaeus vannamei, and observed closely with using light microscope and transmission electron microscope (TEM) for 4-8 days post infection (dpi). As clinical signs, abdominal bodies had mild opaque muscles at 5 dpi. And the mortality was shown at 6 dpi. At 8 dpi, most injected shrimps had severe opaque muscles and humped back that cause of movement disorder. As results of histopathological examinations, local parts of abdominal body muscle had muscle fiber hyalinization, muscle fiber atrophy, rounded muscle fibers, myofibrillar hypertrophy in size, a decrease in number of myofibrils and phagocytosis from the sarcolemmas by multiple hemocytes at 4 dpi. Especially, myofibrillar hypertrophy appeared at the whole or random part of single muscle fiber not in specific locations like the center or edge of muscle fiber. At 6-7 dpi, multiple muscle necrosis, muscle fiber segmentation, myofibril lysis ap- peared and a few hemocytes were infiltrated at lesions. At 8 dpi, extensive muscle necrosis, multiple myofibril lysis and muscle fiber atrophy were shown, and very few hemocytes were infiltrated. In early stage of infection, local viral myositis with zenker's degeneration were shown. These lesions appeared multiply after the early stage. In late stage of infection, extensive coagulative muscle necrosis appeared with few of inflammatory response such as hemocytes infiltration. The lack of hemocytes infiltration response at the late stage might be disadvantage for Litopenaeus vannamei to defense against IMNV and to recover, because hematocytes (granulocyte, semi-granulocyte) eliminate pathogen and damaged tissues from infection sites and help recover. As results of the TEM observation, IMNVs that had nonenveloped icosahedral capsid which was 30-40 nm diameter were in myofibril and beside tubules of sarcoplasmic reticulum and moved to the certain direction. The micro-tears and micro-trau- mas in myofibrils caused muscle fiber necrosis. And semi-granulocytes engulfed IMNVs to eliminate virus.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.5
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• pp.108-115
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• 2014

In this study, experimental approaching method was applied under and single-cylinder engine to research the performance of direct needle-driven piezo injector (DPI) for CR direct-injection. As key-point factor of this DPI that relies on direct-acting operating of injector needle, unlike conventional hydraulic-servo, its nozzle needle can be directly driven by piezo actuator. Thus, effect of direct-acting injection of DPI on diesel combustion and emission characteristics was investigated under common-rail single-cylinder direct-injection engine, equipped with three different driving mechanism, including indirect-acting solenoid, piezo and DPI system. As main results, it found that a direct-acting piezo injector has higher of IMEP. And it has higher heat release rate during premixed combustion and mixing controlled combustion phase due to its higher heat release, even though nitrogen oxide (NOx) formations were increased slightly.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.235-240
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• 2014

Cucumber mosaic virus (CMV) is one of the most important viral diseases in pepper (Capsicum annuum L.), and several genes for resistance were reported in Capsicum spp. In Korea, a single dominant gene that is resistant to $CMV_{Fny}$ and $CMV_{P0}$ has been used for breeding. Recently, a new strain ($CMV_{P1}$) was reported that could infect cultivars resistant to both $CMV_{Fny}$ and $CMV_{P0}$. Therefore, breeding of more robust CMV-resistant cultivars is required. In this study, we surveyed the inheritance of $CMV_{P1}$ resistance and analyzed the location of the resistance loci. After $CMV_{P1}$ inoculation of various germplasms and breeding lines, one accession (ICPN18-8) showed no visual symptoms at 15 dpi (days post inoculation) but was susceptible after 45 dpi, and one resistant line (I7339) showed resistance until at 45 dpi. The latter line was used for tests of resistance inheritance. A total of 189 $F_2$ plants were examined, with 42 individuals showing resistance at 15 dpi and a phenotype segregation ratio close to 1:3 (resistant:susceptible plants). In a lateral ELISA test at 45 dpi, 11 plants showed resistance, and the segregation ratio was changed to 1:15. These results indicate that resistance in C. annuum 'I7339' is controlled by two different recessive genes; we named these resistance genes 'cmr3E' and 'cmr3L,' respectively. To locate these two resistant loci in the pepper linkage map, various RAPD, SSR, and STS markers were screened; only nine markers were grouped into one linkage group (LG). Only one RAPD primer (OPAT16) was distantly linked with cmr3E (22.3 cM) and cmr3L (20.7 cM). To develop more accurate markers for marker-assisted breeding, enriching for molecular markers spanning two loci will be required.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.784-788
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• 2007

Growth hormone-releasing hormone (GHRH), a hypothalamic neuropeptide can stimulate the growth hormone secretion from the anterior pituitary. In this study, a porcine GHRH expression plasmid pHC-GHRH was used to enhance growth performance through ectopic expressions in muscle tissues of rats. Rats injected with the plasmid of pHC-GHRH and pCMV-GHRH exhibited cumulative weight gains 6.4% and 1% greater than controls. During a 5-day period, significant weight gain differences were observed as follows compared with that of control: during 5-10 days post-injection (DPI) period, the group pHC-GHRH on average 14.5% heavier than controls, $40.73{\pm}0.88$ g vs. $35.57{\pm}1.23$ g (p = 0.0023); during 10-15 DPI period, the group pHC-GHRH on average 13.6% heavier than controls, $37.49{\pm}2.85$ g vs. $33.00{\pm}1.56$ g (p = 0.0146); during 15-20 DPI period, the group pHC-GHRH on average 17.8% heavier than controls, $25.64{\pm}1.39$ g vs. $21.77{\pm}1.27$ g (p<0.05). In addition, plasmids-treated rats maintained higher serum IGF-I than controls. Significant differences of IGF-I were observed on 13 DPI and on 40 DPI in pHC-GHRH group compared with that of controls. This was accomplished through the use of an improved expression cassette that included the cytomegalovirus (CMV) immediate early enhancer/promoter in combination with a 1.5-kilobase portion of porcine ${\alpha}$-skeletal muscle actin promoter.

• Animal Bioscience
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• v.37 no.6
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• pp.993-1000
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• 2024

Objective: This study was conducted to investigate the differential expression of the major histocompatibility complex (MHC) gene region in Eimeria-infected broiler. Methods: We profiled gene expression of Eimeria-infected and uninfected ceca of broilers sampled at 4, 7, and 21 days post-infection (dpi) using RNA sequencing. Differentially expressed genes (DEGs) between two sample groups were identified at each time point. DEGs located on chicken chromosome 16 were used for further analysis. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis was conducted for the functional annotation of DEGs. Results: Fourteen significant (false discovery rate <0.1) DEGs were identified at 4 and 7 dpi and categorized into three groups: MHC-Y class I genes, MHC-B region genes, and non-MHC genes. In Eimeria-infected broilers, MHC-Y class I genes were upregulated at 4 dpi but downregulated at 7 dpi. This result implies that MHC-Y class I genes initially activated an immune response, which was then suppressed by Eimeria. Of the MHC-B region genes, the DMB1 gene was upregulated, and TAP-related genes significantly implemented antigen processing for MHC class I at 4 dpi, which was supported by KEGG pathway analysis. Conclusion: This study is the first to investigate MHC gene responses to coccidia infection in chickens using RNA sequencing. MHC-B and MHC-Y genes showed their immune responses in reaction to Eimeria infection. These findings are valuable for understanding chicken MHC gene function.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.30-31
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• 2000

400DPI LED array was fabricated by using reactive ion etching(RIE) method. Material of fabricated LED array was used the GaP for green light emitting and had a homojunction structure. Each cells of emitting area in the LED array were defined with RIE etching for electrical isolation between cells. Electrodes were formed on each cells to emit independently. Ohmic contact resistivity was approximate 1.2$\times$10$^{5}$ $\Omega$/$\textrm{cm}^2$ and 1.26$\times$10$^{5}$ $\Omega$/$\textrm{cm}^2$ using isothermal annealing at 38$0^{\circ}C$ and 43$0^{\circ}C$. Emitting intensity of each etmitting cell was 1.65 cd/$m^2$.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.26 no.2
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• pp.191-200
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• 1996

This study was performed to determine the adequate resolution and compression method in teleradiology. A digital imaging system using Machintosh IT ci computer, 15' Sony high resolution RGB monitor, Umax Power look flatbed scanner with transparency unit and 12 panoramic radiographs were used. The results were as follows : 1. Relative detectability at the group scanned by 30ddpi, 600dpi and 1200dpi was same as those at the real panoramic radiographs. 2. Perceivable image quality degradation was found at the 25％ of middle quality of JPEG compression. But those were not diagnostically significant. 3. Perceivable image quality degradation was found at the 100％ of low quality of JPEG compression. And 8cases among them were diagnostically significant. On the basis of the above results, it is considered that the adequate resolution in scanning radiographs for teleradiology is 300dpi and compression method is the middle quality of JPEG compression.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.180-181
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• 2014

서버 하드웨어 성능 향상과 가상화 소프트웨어 기술의 발달로 클라우드 컴퓨팅 환경은 꾸준히 확산되고 있으며, 이에 따라 인터넷 트래픽 또한 대용량화와 집중화가 진행 중이다. 이와 함께, 지속적인 DDoS 공격 및 사이버테러는 전자정부, 금융, 등 모든 조직을 대상으로 꾸준하게 일어나고 있다. 다양한 사이버테러 공격에 대응하고, 대용량 클라우드 서비스 트래픽을 정밀 분석 하는 정책서버 기반의 서비스별/사용자별/그룹별 트래픽 모니터링 및 제어 관리가 필요하다. 본 논문에서 이를 위한 오픈플로우 기반의 고성능 Open DPI(Deep Packet Inspection) 플랫폼 구조를 제안한다.

• Proceedings of the Korea Multimedia Society Conference
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• 1998.04a
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• pp.154-159
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• 1998

최근의 전자도서관에서 문서영상 데이터베이스를 구축하여 사용자에게 원하는 정보의 원문을 그대로 서비스하고 있는데, 주로 200 dpi 문서영상에 대해 TIFF 영상포맷에서의 ITU-T T.6 압축방법을 사용하고 있다. 본 연구에서는, 문서영상 데이터베이스의 확장성, 지속성, 효율성 등을 고려하여, 문서 영상의 스캐닝 해상도의 600 dpi가 적당하며, 압축방법은 JBIG이 타당함을 제시하였다. 아울러, 모니터 및 프린터 기반 서비스의 특성을 분석하여 서비스 해상도를 차별화하는 방법인 단계별 서비스 방안을 제시함으로써 JBIG의 단점인 과다한 복구시간 문제를 해결하였다. 대표적인 문서영상들에 대한 실험을 통해, JBIG의 높은 압축율 및 제시된 단계별 서비스 방안의 타당성을 확인하였다.