• 대한수의학회지
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• 제41권3호
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• pp.311-317
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• 2001

In this work we have investigated the physiological effects of $MgCl_2$ in isolated atrium, papillary muscle, perfused heart and anesthesized guinea pig, The addition or infusion of $MgCl_2$ (0~20 mM or mg/kg) to perfused hearts and to anesthesized guinea pigs induced a marked and dose-dependent negative chronotropic effect. The sinoatrial node automaticity could also be reduced by $MgCl_2$. The addition of $MgCl_2$to isolated atria and to papillary muscles induced a marked and dose-dependent negative inotropic effect. The threshold voltage could be increased by $MgCl_2$in papillary muscle. Increasing $MgCl_2$ shortened the action potential duration (APD) in dose-dependent manner at 30% ($APD_{30}$) and 90% repolarization ($APD_{90}$) measured with conventional microelectrode technique in papillary muscle. In anesthesized guinea pig, the magnesium infusion resulted in a dose-dependent drop in blood pressure. These results suggested that magnesium is closely associated with cardiac physiological condition and exerts antiarrhythmic activities.

• Parasites, Hosts and Diseases
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• 제58권6호
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• pp.689-694
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• 2020

Strongyloidiasis is caused by Strongyloides stercoralis and is one of the most neglected tropical diseases in tropical and subtropical regions. Although several strongyloidiasis cases have been reported in Korea, genetic analysis of Korean isolates is still incomplete. In this study, a parasite was isolated from a 61-year-old man diagnosed with strongyloidiasis during the treatment of lymphoma on his retroperitoneal lymph node. Diffuse symmetric wall thickening from the ascending to descending colon and a nematode-infected intestine was observed following microscopic examination. Genomic DNA was isolated from a patient tissue block, and S. stercoralis was identified by PCR and sequencing (18S rDNA). In order to determine phylogenetic location of a Korean isolate (named KS1), we analyzed cox1 gene (500-bp) and compared it with that from 47 previous S. stercoralis isolates (28 human isolates and 19 canid isolates) from Asian countries. Our results showed that phylogenetic tree could clearly be divided into 5 different groups according to hosts and regions. KS1 was most closely related with the Chinese isolates in terms of genetic distance.

• Structural Engineering and Mechanics
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• 제10권1호
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• pp.81-92
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• 2000

This study is an investigation of the effect of cracks on the dynamical characteristics of a cantilever beam, having multiple open-edge transverse cracks. The flexibilities due to crack have been identified for several crack depths and locations. In the study the finite element method and component mode synthesis methods are used. Coupling the components is performed by a flexibility matrix taking into account the interaction forces. Each component is modelled by cantilever beam finite elements with two nodes and three degrees of freedom at each node. The results obtained lead to conclusion that, by using the drop in the natural frequencies and the change in the mode shapes, the presence and nature of cracks in a structure can be detected. There is some counter-evidence, however, that the effects due to multiple cracks may interact to make detection more difficult than for isolated cracks.

• 한국통신학회논문지
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• 제15권9호
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• pp.738-744
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• 1990

본 논문은 음성신호의 실시간 저장법과 기존 표본 데이터에서 개선된 표본 데이터 방법을 제안하여, 신경회로망의 역전파 학습 알고리즘을 이용한 고립 단어 음성인식 시스템에 대하여 연구하였다. 각 층의 노드 수 변화에 의한 기존 표본 데이터방식과 새로운 표본 데이터 방식에서의 인식률과 에러율 변화를 비교하였다. 본 연구 결과, 인식률은 95.1%를 얻었다.

• 전자통신동향분석
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• 제36권4호
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• pp.13-22
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• 2021

Among the activities of 3GPP for operating 5G-based unmanned aerial vehicles, we introduce several use cases of UAVs in 5G mobile communication such as radio access node onboard UAV, simultaneous support data transmission for UAVs and eMBB users, autonomous UAVs controlled by AI, isolated deployment of radio access through UAV, and separation of UAV service area. From this, we further summarize 5G mobile communication requirements for UAVs, including definition and operational criteria of UAS, UAS remote identification requirements, UAS usage requirements, and performance requirements. Finally, regarding 5G mobile communication-based UAS connectivity, identification and tracking support, we discuss the 3GPP UAV architecture, seven major problems, the proposed solutions to each problem, and propose the results for future specification work.

• 한국동물위생학회지
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• 제44권4호
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• pp.321-326
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• 2021

The study characterized Trueperella pyogenes (T. pyogenes) from caseous lymphadenitis (CLA) in Korean native goats (KNG). CLA samples (n=191) were obtained from abattoir-slaughtered KNG. Pus were obtained and Corynebacterium pseudotuberculosis was detected by PCR using PLD gene. Three PLD-negative samples (1.57%) from supramammary lymph node were subjected to bacterial culture. Isolates were identified using 16S rRNA and biochemically characterized by APIZYM. Phylogenetic and biochemical analyses identified the isolates as T. pyogenes, and have shown separate clusters and varied enzyme reaction, suggesting genotypic and phenotypic diversity. This first report of T. pyogenes-induced CLA in KNG provided information for further investigations.

• 환경생물
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• 제30권3호
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• pp.164-172
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• 2012

우리나라 최대 담수호인 소양호에 존재하는 미생물 중 Flavobacterium을 분리하여 그 특징을 조사하였다. 그 중에서 97%와 98% 사이의 상동성을 지니는 Flavobacterium을 대상으로 21종을 선택하였으며, 그 균주들의 생리학적, 생태학적 위치를 살펴보았다. 그 결과, 소양호에 존재하는 21종의 분리된 Flavobacterium은 4개의 주된 node에 위치하였으며, 그 중에서 대부분이 하나의 group에 속하여 있었다. 각 Flavoacterium 21종의 생리적인 특징은 기존의 보고된 Flavoacterium들과는 서로 다른 특징을 지니지만, total fatty acid의 분석결과 iso $C_{15:0}$과 summed feature 3 (comprised $C_{16:1}$ ${\omega}7c$ and/or $C_{16:1}$ ${\omega}6c$)가 주요 성분으로 전형적인 Flavobacterium의 특징을 지닌 것으로 나타났다. 따라서 소양호내에는 유전적 유연관계가 있는 아변종의 Flavobacterium이 존재하며, 기존에 알려진 종들과는 다른 형질을 가지고 있는 것으로 보아 소양호 생태계의 생물 종 다양성이 유지되고 있는 것으로 판단된다.

• Tuberculosis and Respiratory Diseases
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• 제75권3호
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• pp.116-119
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• 2013

Sarcoidosis, a systemic granulomatous disease of unknown etiology. The presentation of sarcoidal granuloma in neck nodes without typical manifestations of systemic sarcoidosis is difficult to diagnose. We describe the case of a 37-year-old woman with an increasing mass on the right side of neck. The excisional biopsy from the neck mass showed noncaseating epithelioid cell granuloma of the lymph nodes. No evidence of mycobacterial or fungal infection was noted. Thoracic evaluations did not show enlargement of mediastinal lymph nodes or parenchymal abnormalities. Immunohistochemistry showed abundant expression of tumor necrosis factor-${\alpha}$ in the granuloma. However, transforming growth factor-${\beta}$ was not expressed, although interleukin-$1{\beta}$ was focally expressed. These immunohistochemical findings supported characterization of the granuloma and the diagnosis of sarcoidosis. Sarcoidosis can present with cervical lymph node enlargement without mediastinal or lung abnormality. Immunohistochemistry may support the diagnosis of sarcoidosis and characterization of granuloma.

• 대한수의학회지
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• 제43권3호
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• pp.463-469
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• 2003

Eight nursery to grower pigs exhibiting weight loss and sudden death were diagnosed as postweaning multisystemic wasting syndrome (PMWS) based on the results of gross findings, histopathology, immunohistochemistry, fluorescent antibody test, virus isolation, PCR, serology, and electron microscopy. Groosly, the pigs had a rough hair coats and were severely emaciated. And moot lymph nodes were pale and enlarged. Lungs were not fully collapsed and exhibited 10 to 40% pale red cranioventral consolidation. Histopathologically, typical lymphohistiocytic interstitial to bronchointerstitial pneumonia, chronic lymphadenitis, severe lymphoid depletion, and basophilic intracytoplasmic inclusions were noted in the most lymphoid tissues. Porcine circovirus panicles were observed in the inguinal lymph node of the pigs by electron microscopy. Porcine circovirus type 2 (PCV2) antigens or viral DNAs were detected in the lesions of all pigs using immunohistochemistry or PCR. Two PCV2 were isolated from a homogenate of pooled lung and lymph node in 2 of the 5 pigs. Additionally, antigens of porcine reproductive and respiratory syndrome virus (PRRSV) and Hemophilus (H.) parasuis were also detected by immunofluorescent antibody test. Serologically, 55% of randomly selected sows and fattening pigs was serum antibody positive to PCV2 by an indirect fluorescent antibody (IFA) test and approximately 18 % of animals in the herd were serologically pooitive by the ELISA kit for PRRSV. To our knowledge, this is the first report of PMWS co-infected with PCV-2, PRRS, and H. parasuis in Korea.

• 한국통신학회논문지
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• 제32권12B호
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• pp.719-727
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• 2007

무선 메쉬 네트워크(Wireless Mesh Network) 기술은 유선을 설치하기 힘든 섬지역이나, 군의 전장지역과 같은 법은 지역에 저렴한 비용으로 인프라를 제공할 수 있다. 그러나 무선 메쉬 네트워크에서는 다중 홉 통신 환경에서 홉 수의 증가로 인한 성능의 급격한 감소는 물론 지연이 급격히 증가되는 결과를 초래하고 있다. 군 환경에 무선 메쉬 네트워크의 적용을 고려할 때 게이트웨이를 통하는 음성이나 동영상과 같은 실시간 데이터 트래픽이 많은 부분을 차지할 것으로 볼 때, 원거리 부대 AP에 연결된 메쉬 단말들은 실시간 서비스 받기가 제한이 된다. 이로 인해 공정성에 대한 문제가 발생하게 된다. 본 논문에서는 이 문제 해결을 위해 각 제대별 AP에 연결된 모든 메쉬 노드에 공정한 QoS를 제공할 수 있고, 군의 특성을 고려한 긴급정보나 Control 패킷에 우선순위(가중치)를 부여할 수 있는 WRR(Weight Round Robin) 방식을 기본으로 동작하는 위치기반 패킷 스케줄링 방식을 제안하여 성능을 검증하였다.