• Title/Summary/Keyword: Burst

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Optimal Weapon-Target Assignment Algorithm for Closed-In Weapon Systems Considering Variable Burst Time (가변 연속사격 시간을 고려한 근접 방어 시스템의 최적 무장 할당 알고리듬)

  • Kim, Bosoek;Lee, Chang-Hun;Tahk, Min-Jea;Kim, Da-Sol;Kim, Sang-Hyun;Lee, Hyun-Seok
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.5
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    • pp.365-372
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    • 2021
  • This paper deals with an optimal Weapon-Target Assignment (WTA) algorithm for Closed-In Weapon Systems (CIWS), considering variable burst time. In this study, the WTA problem for CIWS is formulated based on Mixed Integer Linear Programming (MILP). Unlike the previous study assuming that the burst time is fixed regardless of the engagement range, the proposed method utilizes the variable burst time based on the kill probability according to the engagement range. Thus, the proposed method can reflect a more realistic engagement situation and reduce the reaction time of CIWS against targets, compared to the existing method. In this paper, we first reformulate the existing MILP-based WTA problem to accommodate the variable burst Time. The proposed method is then validated through numerical simulations with the help of a commercial optimization tool.

A Comparison of Blast Load in a Simplified Analytical Model of Rigid Column (강체 기둥의 단순 해석 모델에서의 폭발 하중 비교)

  • Park, Hoon
    • Explosives and Blasting
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    • v.37 no.3
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    • pp.1-12
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    • 2019
  • The analysis methods of blast analysis models are classified into direct analysis and indirect analysis, and the latter is divided into semi-empirical and numerical analysis methods. In order to evaluate the applicability of the ELS blast analysis program, which is a program for analyzing the semi-empirical models, this study selected a simplified analytical model and examined the blast load characteristics of free-air burst explosion and surface burst explosion by using AT-Blast, RC-Blast, and Kinney and Graham's empirical equations, which are the semi-empirical analysis programs. As a result of analyzing the explosion pressure for the scaled distance and the incidence angle for the simplified analytical model, an appropriate analysis can be performed when the range of the scaled distance in the free-air burst explosion analysis was 0.3~0.461 and when the range of the scaled distance in the surface burst explosion analysis was 0.378~0.581. In terms of the incidence angle, the results analyzed within $45^{\circ}$ were considered to be appropriate.

Effects of Red Ginseng Extracts on Hydrogen Peroxide Production of Murine Prtitoneal Macrophages (홍삼추출물이 마우스 복강 대식세포 Hydrogen Peroxide 생산에 미치는 영향)

  • 박란숙
    • The Korean Journal of Food And Nutrition
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    • v.11 no.1
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    • pp.107-113
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    • 1998
  • This experiment has conducted to evaluate whether single injection of red ginseng extract including 50% ethanol extract, crude saponin, and lipid soluble fraction can induce oxidative burst of mouse peritoneal macrophages with use of fluorescence spectrophotometer. To optimize conditions of fluorescent spectrophotometry, concentrations of DCFH-DA(2', 7' -dichlorofluorescin diacetate) was 1.6 ${\mu}{\textrm}{m}$ and control oxidative burst by Zymosan A and PMA(phorbol myristate acetate) were 100$\mu\textrm{g}$, 250ng, respectively. Though in vitro macrophages failed to induce increment of H2O2 production, but 50% ethanol extract group induced significant enhancement of H2O2 production when zymosan A triggered oxidative burst. On the other hand, lipid soluble fraction enhanced significantly H2O2 production than that of control group. These findings consisted with the other reports which showed ginsenosides inhibited nitric oxide production and lipid soluble fraction activated colony stimulating factor(granulocyte - monocyte) activity in bone marrow stem cells. As is well known, lipid soluble fraction contains phenol compound, polyacetylene compound and alkaloids. Further study would unravel which component of it can induce H2O2 production of macrophages. Key words : Red ginseng(Panax ginseng), H2O2 production, macrophages.

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QoS Gurantieeing Scheme based on Deflection Routing in the Optical Burst Switching Networks (광 버스트 교환망에서 우회 라우팅을 이용한 QoS 보장 방법)

  • Kim, Jong-Won;Kim, Jung-Youp;Choi, Young-Bok
    • The KIPS Transactions:PartC
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    • v.10C no.4
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    • pp.447-454
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    • 2003
  • Optical burst switching (OBS) has been proposed to reduce the use of fiber delay lines (FDLs) and to realize the optical switching paradigm of the next-generation ail optical networks. The OBS can provide improvements over wavelength routing in terms of bandwidth efficiency and core network scalability via statistical multiplexing of bursts. Recently, another challenging issue is how to upport quality of service (QoS) in the optical burst switching networks. In this paper, we propose a deflection routing scheme to guarantee the QoS for the OBS networks to detour lower priority burst forward to the deflection routing path when congested. A big advantage of the proposed scheme is the simplicity of QoS provision, that comes from the simple QoS provisioning algorithm. Also, the QoS provisioning scheme be able to make efficient networks by fairly traffic distributing with the reduce of the use of FDLs at core routers. The QoS provisioning scheme has been verified to reliably guarantee the QoS of priority 0, 1, 2 burst and to efficiently utilize network resources by computer simulations using OPNET As results, the end-to-end delay of high priority burst is improved, and the network efficiency is also improved.

Magnaporthe oryzae Effector AVR-Pii Helps to Establish Compatibility by Inhibition of the Rice NADP-Malic Enzyme Resulting in Disruption of Oxidative Burst and Host Innate Immunity

  • Singh, Raksha;Dangol, Sarmina;Chen, Yafei;Choi, Jihyun;Cho, Yoon-Seong;Lee, Jea-Eun;Choi, Mi-Ok;Jwa, Nam-Soo
    • Molecules and Cells
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    • v.39 no.5
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    • pp.426-438
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    • 2016
  • Plant disease resistance occurs as a hypersensitive response (HR) at the site of attempted pathogen invasion. This specific event is initiated in response to recognition of pathogen-associated molecular pattern (PAMP) and subsequent PAMP-triggered immunity (PTI) and effector-triggered immunity (ETI). Both PTI and ETI mechanisms are tightly connected with reactive oxygen species (ROS) production and disease resistance that involves distinct biphasic ROS production as one of its pivotal plant immune responses. This unique oxidative burst is strongly dependent on the resistant cultivars because a monophasic ROS burst is a hallmark of the susceptible cultivars. However, the cause of the differential ROS burst remains unknown. In the study here, we revealed the plausible underlying mechanism of the differential ROS burst through functional understanding of the Magnaporthe oryzae (M. oryzae) AVR effector, AVR-Pii. We performed yeast two-hybrid (Y2H) screening using AVR-Pii as bait and isolated rice NADP-malic enzyme2 (Os-NADP-ME2) as the rice target protein. To our surprise, deletion of the rice Os-NADP-ME2 gene in a resistant rice cultivar disrupted innate immunity against the rice blast fungus. Malic enzyme activity and inhibition studies demonstrated that AVR-Pii proteins specifically inhibit in vitro NADP-ME activity. Overall, we demonstrate that rice blast fungus, M. oryzae attenuates the host ROS burst via AVR-Pii-mediated inhibition of Os-NADP-ME2, which is indispensable in ROS metabolism for the innate immunity of rice. This characterization of the regulation of the host oxidative burst will help to elucidate how the products of AVR genes function associated with virulence of the pathogen.

Improvement of duty rate of Meteor Burst communication with Buried Antenna (매설형 안테나를 이용한 유성 버스트 통신의 도통율 개선)

  • 김병철;이영철;김기채
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 1999.05a
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    • pp.254-260
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    • 1999
  • Meteor Burst Communication can provide effective and economical means of communication where long distance VHF NLOS data transmission is needed; often ranges more than 1000 km. It has been, however, so far considered unsuitable for short distance application because of phenomenal decrease in burst durations, which leads to decreation of total duty rate of the system. This paper extensively analyzes characteristics of shot distance MB(Meteor Burst) path and shows the low duty rate may be improved by increasing burst rate through adapting antenna beam width to cover entire hot-spot region in the space and, by compensating effective burst length through cutting down man-made noises introduced by antenna. Based on the analysis, we are developed a small-opening-cavity antenna, especially designed for short distance MB path. In operation, the antenna is to be buried under ground surface so as to improve directivity and reduces noise introduction. The antenna exhibits power gain of 3 dB with 90 degree beam width and thus enables to illuminate entire hot-spot regions with the elevation angle of 8-90 degree which is the case of transmission less than 100 km. Directivity horizontal to earth surface is suppressed to minimum which enables to cut man-made noises from near-by sources down to more than 3 dB from the level reported with conventional 4 element Yagi. A series of experiments performed on 100 km MB paths have conformed that, with the antenna installed at receiving site, the burst rate and duration time have been noticed to increase by 10 and 20 percent respectively from the values obtained by conventional 4-element Yagi antenna under same testing condition.

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Performance Evaluation and Offset Time Decision for Supporting Differential Multiple Services in Optical Burst Switched Networks (광 버스트 교환 망에서 차등적 다중 서비스 제공을 위한 offset 시간 결정 및 성능 평가)

  • So W.H.;im Y.C.K
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.1
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    • pp.1-12
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    • 2004
  • In this paper, we take advantage of the characteristics of optical burst switching (OBS) to support service-differentiation in optical networks. With the offset time between control packet and burst data, the proposed scheme uses different offset time of each service class. As contrasted with the Previous method, in which the high Priority service use only long offset time, it derives the burst loss rate as a QoS parameter in consideration of conservation law and given service-differential ratios and decides a reasonable offset time for this QoS finally Firstly proposed method classifies services into one of high or low class and is an algorithm deciding the offset time for supporting the required QoS of high class. In order to consider the multi-classes environment, we expand the analysis method of first algorithm and propose the second algorithm. It divides services into one of high or low group according to their burst loss rate and decides the offset time for high group, and lastly cumulates the offset time of each class. The proposed algorithms are evaluated through simulation. The result of simulation is compared with that of analysis to verify the proposed scheme.

Improvement of Short Range Performance of Meteor Burst Path with Buried Antenna (지하 매설형 안테나를 이용한 근거리 유성 버스트 통신의 특성개선)

  • 김병철;김기채;이무영
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.9 no.6
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    • pp.788-801
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    • 1998
  • Meteor Burst Communication can provide effective and economical means of communication where long distance VHF NLOS data transmission is needed ; often ranges more than 1000 km. It has been, however, so far considered unsuitable for short distance application because of phenomenal decrease in burst durations, which leads to decreation of total duty rate of the system. This paper extensively analyzes characteristics of shot distance MB(Meteor Burst) path and shows the low duty rate may be improved by increasing burst rate through adapting antennal beam width to cover entire hot-spot region in the space and, by compensating effective burst length throughcutting down man-made noises introduced by antennal. Based on the analysis, we are developed a small-opening-cavity antennal, especially designed for short distance MB path. In operation, the antenna is to be buried under ground surface so as to improve directivity and reduces noise introduction. The antennal exhibits power gain of 3 dB with 90 degree beam width and thus enables to illuminate entire hot-spot regions with the elevation angle of 8-90 degree which is the case of transmission less than 100 km. Directivity horizontal to earth surface is suppressed to minimum which enables to cut man-made noises from near-by sources down to more than 3 dB from the level reported with conventional 4 element Yagi. A series of experiments performed on 100km MB paths have conformed that, with the antenna installed at receiving site, the burst rate and duration time have been noticed to increase by 10 and 20 percent respectively from the values obtained by conventional 4-element Yagi antennal under same testing condition.

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