• Title/Summary/Keyword: IFA.

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Evaluating and Mitigating Malicious Data Aggregates in Named Data Networking

  • Wang, Kai;Bao, Wei;Wang, Yingjie;Tong, Xiangrong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.9
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    • pp.4641-4657
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    • 2017
  • Named Data Networking (NDN) has emerged and become one of the most promising architectures for future Internet. However, like traditional IP-based networking paradigm, NDN may not evade some typical network threats such as malicious data aggregates (MDA), which may lead to bandwidth exhaustion, traffic congestion and router overload. This paper firstly analyzes the damage effect of MDA using realistic simulations in large-scale network topology, showing that it is not just theoretical, and then designs a fine-grained MDA mitigation mechanism (MDAM) based on the cooperation between routers via alert messages. Simulations results show that MDAM can significantly reduce the Pending Interest Table overload in involved routers, and bring in normal data-returning rate and data-retrieval delay.

Ultra-small Marker Beacon Antenna with a Wide Frequency Tuneable Capacitive Plate

  • Park, Ju-Derk;Choi, Byeong-Cheol;Kim, Nam;Jung, Young-Bae
    • ETRI Journal
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    • v.38 no.5
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    • pp.879-884
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    • 2016
  • In this paper, an ultra-small marker beacon antenna operated in the VHF-band is proposed. This antenna has a modified linear IFA structure with a lumped capacitor and a capacitive plate for frequency tuning and impedance matching. The capacitive plate is directly connected to the end of a linear radiator and is separated from the antenna ground by 1 mm. The main operating frequency is mainly controlled by the size and dielectric constant of the capacitive plate. The lumped capacitor is useful for fine frequency tuning. Using the proposed structure, an ultra-small marker beacon antenna can be realized with a length of 0.04 ${\lambda}_0$.

The Observability Analysis of SDINS on The Trajectory for The In-Flight Alignments (스트랩다운 관성항법 시스템의 운항 중 정렬을 위한 궤적에 따른 가관측성 분석)

  • Park, Joon-Goo;Lee, Jang-Gyu;Park, Chan-Gook;Chung, Do-Hyung
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.1002-1004
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    • 1996
  • In this paper, presented are the results of observability analysis for the vehicle maneuver during In-Flight Alignment of SDINS. The target system for observability analysis is 10th order one. Three trajectories for IFA are considered. To analyze the observability of the time varying system, correlation coefficient is used and to measure the degree of observability of the given system, simulation is carried out using covariance matrix. The results of simulation show that trajectories which are having continuous changes in attitude and acceleration of system is superior to straight trajectory in correcting navigation errors.

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Antibody reaction of human anti-Toxoplasma gondii positive and negative sera with Neospora caninum antigens (톡소포자충 양성 및 음성인 사람 혈청에 대한 네오포자충 (Neospora caninum))

  • Ho-Woo NAM;Seung-Won KANG;Won-Young CHOI
    • Parasites, Hosts and Diseases
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    • v.36 no.4
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    • pp.269-275
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    • 1998
  • Anti-Neospora caninum antibody was detected in anti-Toxoplasma gondii positive and negative human sera by ELISA, western blot and immunofluorescence assay (IFA). Twelve cases out of 172 (6.7%) Toxoplasma-positive sera cross-reacted with both T. gondii and N. caninum antigens, and one out of 110 Toxoplasma-negative sera reacted with N. caninum antigen by ELISA. By western blot, all 12 sera reacted with T. gondii antigens with various banding patterns but specifically at 30 kDa (SAG 1), and 22 kDa (SAG2) bands. With N. caninum antigen, the number of reactive bands was reduced, however a 43 kDa band reacted in three cases in Toxoplasma-positive sera in addition to one in Toxoplasma-negative control sera. All sera of the Toxoplasma-positive group labeled surface membrane of T. gondii, but reacted differently with N. caninum. Fluorescence was detected in surface membrane, subcellular organelles, or both in N. caninum. And one case in the Toxoplasma-negative group also reacted with N. caninum strongly in subcellular organelles. This suggested that the antibody against N. caninum may be present in human sera although the positive rate was very low in this study. The possibility of human infection with N. caninum remains to be evaluated further.

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Hematological Change of Korean Native Goats Experimentally Infected with Bovine Leukemia Virus (Bovine Leukemia Virus에 실험감염된 한국재래산양의 혈액상의 변동)

  • 이필돈;김종호;전무형
    • Korean Journal of Veterinary Service
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    • v.18 no.1
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    • pp.1-21
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    • 1995
  • To elucidate pathogenesis of bovine leukemia virus(BLV) in Korean native goats, the goats experimentally infected with BLV were studied especially for the aspects of infectivity and hematological changes. The experimental goats were examined for 27 months by agar-gel immunodiffusion(AGID) test and syncytium formation assay. During this period, changes of total leucocyte, absolute Iymphocyte and atypical Iymphocyte were examined, and the distribution of surface immunoglobulin ( sIg ) -bearing cells and rosette forming cell (RFC) in the peripheral Iymphocyte were also investigated. By indirect immunofluorescence (IFA) and complement dependent antibody cytotoxicity (CDAC) assay using monoclonal antibody(Mab) against bovine leukosis tumor-associated anti-gen(BL-TAA), changes of BL-TAA positive Iymphocyte in peripheral blood were measured. The results obtained through the experiment were summarized as follows. 1. Antibody titers were measured by AGID using gP51 and P24 antigens. The animals were serologically converted at 2 months post-inoculation(pi) in gP51 antigen, whereas sero-converted at 4 months pi in P24 antigen. In comparison with antibody titers for gP51, P24 antigen showed lower titers throughout the trial period. 2. The peripheral lymphocytes from all of the infected goats, as co-cultivated with F8l cells manifested syncytial formation at 4 months pi. 3. On counting total leucocyte, Iymphocyte and atypical Iymphocyte, two out of four infected goats showed normal distribution, while No 2 of the remaining two revealed temporal and No 3, Persistant increasing number of the cells. 4. The optimal condition of rosette formation of the peripheral Iymphocyte of normal Korean native goats was shown in the sheep erythrocyte treated with 0.1M AET for 30 nun at $37^{\circ}C$. When the Iymphocytes were treated in nylon wool column, the number of sIg-bear-ing cell were increased in the nylon wool adherent cells, but RFC was increased in the non-adherent cells. Of the infected goats, No 2 and No 3 showed significantly increasing number of sIg-bearing cells at 18 months pi. 5. The Iymphocytes of No 2 and No 3 goats reacted positively in IFA using Mab against BL-TAA at 12 months pi and 18 months pi, respectively. In CDAC test, all of four infected goats revealed positive reaction at 24 months pi. The higher positive rates were observed in No 2 and No 3 as compared with the remainders.

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Seroepidemiologic Evidence for the Presence of Hantavirus in South Africa (남아프라카 지역내 한타바이러스 존재에 관한 혈청 역학적 증거)

  • Lee, Pyung-Woo;Park, Man-Seong;Keen, G.Anthony;Noveljic, Z.;Tucker, Tim J.;Ryst, Elna van der;Viljoen, Johannes I.;Pretorius, Anne-Marie;Oelofsen, Mike
    • The Journal of Korean Society of Virology
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    • v.29 no.1
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    • pp.11-22
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    • 1999
  • Sero-epidemiologic survey has been carried out to establish serologically the presence of hantavirus in areas of South Africa. The survey was oriented to search natural infection in both of humans and wild rodents and involvement of human disease. The normal human sera were collected from the residents in urban and rural areas of Western Cape, and rural area of Eastern Cape province. The rodent sera came from various species of rodents trapped in Northern Cape and Western Free provinces. The patient sera were selected from the patients of renal failure, pulmonary syndrome and pyrexia of unknown origin (PUQ) according to diagnostic chart among the patients hospitalized in major hospitals of Cape Town area. The sera were screened and titrated by IFA test using antigens of Hantaan (HTN), Seoul (SEO), Puumala (PUU), and Prospect Hill (PH) viruses primarily. Positive cases were subjected to differential IFA test using HTN, PUU and PH antigens and plaque reduction neutralization test for further confirmation. Anti-hantavirus antibodies were detected from 2 of 352 rural, 1 of 172 urban residents of E. Cape, and 5 of 118 rural, 5 of 368 urban residents of W. Cape. The antibody was also demonstrated from 5 of 221 wild rodents, and it was appeared that 2 different species, Aethomys namaquensis and Tatem leucogaster, are involved. Among 318 patients tested, 3 who were diagnosed as chronic renal failure, acute respiratory distress syndrome (ARDS) and glomerulonephritis were proved to be positive. The reaction patterns obtained from all of these positive sera were distinct from hantaviral sero-patterns ever established. This result suggests that new viruses may exist in this area and play an possible etiologic role in human disease. The feature of serologic survey on anti-hantavirus antibody demonstrable newly from African wild rodents which are different from reservoir species in other continents elicits a conjecture that the virus may be different from known hantaviruses ever found. This fact also suggests that an expanded role in etiologic involvement with other unknown human diseases by newly emerging hantaviruses may be possible in this areas.

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Serodiagnosis of cysticercosis by ELISA-inhibition test using monoclonal antibodies (단세포군항체를 이용한 효소면역억제측정 법에 의한 유구낭미충증의 혈청학적 진단)

  • 용태순;여인석
    • Parasites, Hosts and Diseases
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    • v.31 no.2
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    • pp.149-156
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    • 1993
  • Monoclonal antibodies (Mabs) were produced against crude scolex extract of T solium metacestodes, and applied to ELISA-inhibition test for improving the specificity of serodiagnosis of human cysticercosis. Four hybridomas secreting species-specific anti- cysticercal Mabs (Cya-1, Cya-7, Cya-28 and Cya-31) were selected. Each Mab reacted on antigenic components of 25.5 kDa (Cya-1), 28 kDa (rcya-7), 87.5 kDa (Cya-281), and 12.5 kDa (Cya-31). IFA showed that Cya-1 was located at the calcium corpuscles, and Cya-7 at the loose connective tissue of T soLium metacestode scolex. Cya-28 and Cya-31 reacted on the tegument of the scolex. By conventional ELISA, 23 out of 28 (82.1%) cysticercosis patients were found serologically positive, but 1 out of 9 (11.1%) sparganosls cases and 6 out of 31 (19.4%) paragonlmiasis cases showed false positives. By ELISA-Inhibition test using species-specific anti-cysticercal Mab Cya-7, 19 out of 28 (67.9%) cystlcercosis cases were found serologically positive, but there were no false positives In other parasitic infections.

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A Study on the Enhancement of Isolation of the MIMO Antenna for LTE/DCS1800/USPCS1900 Handset (LTE/DCS1800/USPCS1900 단말기용 MIMO 안테나의 격리도 개선에 관한 연구)

  • Cho, Dong-Ki;Son, Ho-Cheol;Lee, Jin-Woo;Lee, Sang-Woon;Lee, Mun-Soo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.10
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    • pp.80-85
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    • 2010
  • In this paper, a MIMO antenna is proposed for LTE/DCSl800/USPCSl900 handset applications. The proposed antenna is based on the IFA and its wide bandwidth is obtained by using a stagger tuning technique. To improve the isolation, a suspended line is connected to the shorting points in two antennas, and capacitors and inductors are added to the connected suspended line. Two identical antennas of which dimension is 2.8cc($40{\times}10{\times}7mm$) are mounted on the two end lines of the system ground plane($40{\times}60mm$). Analysis of the antenna performance and optimization is performed using CST Microwave Studio. The bandwidths are satisfied for LTE band class 13(746-787MHz), class 14(758-798MHz) and DCSl800/USPCSl900 band (1710-1990MHz). The isolations between two antennas are about -12dB for LTE band and -10dB for DCSl800/USPCSl900 band. And the radiation efficiency of each antenna is about for LTE band 33% and 45% for DCSl800/USPCSl900 band respectively.

Seroprevalence and risk factors of Lyme disease among Korean deer farmers (대한민국 사슴농가 종사자의 라임병 혈청유병률 및 위험요인)

  • Acharya, Dilaram;Cho, Jae-Hak;Yoo, Seok-Ju;Park, Ji-Hyuk
    • Journal of agricultural medicine and community health
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    • v.44 no.2
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    • pp.82-89
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    • 2019
  • This study was undertaken to determine the seroprevalence and risk factors associated with contracting Lyme disease (LD) among Korean deer farmers. This cross-sectional study devised questionnaire that addressed farm activities, was devised and the blood samples of 516 Korean deer farmers were tested. LD seroprevalence was determined by Western blot test. Fisher's exact test, the chi-squared test, and the chi-squared test for trend analysis were performed to assess the risk associated with LD. Of total 516 study participants recruited, only 12 (2.3%) were seropositive for LD. The result of the study revealed that only deer farmers raising Elk (Cervus Canadensis) were found to be at significantly higher risk of contracting LD than other deer farmers (p=0.033). In addition, a male sex, an age of < 40 years, and those that had raised deer for < 19 years had higher rates of LD infection than their counterparts. Similarly, those that managed livestock sheds, fed deer, processed industry and prepared compost had higher rates of LD infection. In terms of protective factors, those who did not use protective measures such as wear glasses and masks, or protective gloves and aprons, and those that did not disinfect work instruments and did not shower after work had higher rates of LD than those that used protective measures. In conclusion, preventive health strategies should take into account the profiles of deer farmers at greater risk based on considerations of personal, type of work, and the use of personal protective measures.

UHF Band RFID Tag Antenna Mountable on metallic Object (금속에 부착 가능한 UHF 대역 RFID 태그 안테나)

  • Jung Jun-Mo;Yu Byung-Gil;Jung Byung-Woon;Lee Byung-Je
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.5 no.1 s.9
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    • pp.65-70
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    • 2006
  • A UHF band RFID passive tag antenna, which can be attached on metallic objects, is proposed. The proposed tag antenna is more insensitive to the size of the metallic object than conventional PIFAs or IFAs. It is constructed on a multi-layer and its size is reduced by using a 'L' slit. Performances of the antenna is analyzed by Ansoft's HFSS and measured using a back-scattering method. The simulated and measured data are obtained with varying the size of metallic object.

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