• 제목/요약/키워드: Counter Chain

검색결과 39건 처리시간 0.022초

Effect of Mirror Misalignments on Optical Ray Path In a Ring Resonator

  • Lee, Dong-Chan;Lee, Jae-Cheul;Son, Seong-Hyun;Cho, Hyun-Ju
    • Journal of the Optical Society of Korea
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    • 제6권3호
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    • pp.121-127
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    • 2002
  • The operating principal of a ring laser gyroscope depends on the phase difference for the counter-propagating waves within a closed path. The reflecting mirrors mounted on the monoblock form the traveling waves. The manufacturing accuracy of the monoblock influences the traveling path of ray, the sensitivity of laser resonator for misalignments, and diffraction losses. A 3 $\times$ 3 ray transfer matrix was derived for optical components with centering and squaring errors in a ring resonator. The matrix can be utilized to predict the optical ray paths on the basis of the manufacturing errors of the monoblock as well as the misalignment of mirrors. Then the distance and orientation (o. slope) at the arbitrary plane inside the resonator along the ideal optical path can be calculated from the chain multiplication of the ray transfer matrix for each optical component in one round trip. We also show that the counter-propagating rays In a ring resonator with errors does not coincide in each round trip, which results in gain difference between two beams, and how these errors can be adjusted through the alignment procedure. Finally this 3 $\times$ 3 ray matrix formalism can be used to calculate the beam size and its displacement from the optical axis and the deviation at the diaphragm.

북한 비대칭 위협 대응한 한국 해군전력 발전방향 (Directions of ROK Navy's Future Developments in Responding to Asymmetric Threats posed by North Korea)

  • 부형욱
    • Strategy21
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    • 통권40호
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    • pp.190-215
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    • 2016
  • As North Korea's asymmetric threats are growing, there have been numerous discussions to find out effective counter-measures and many official plans and procurements efforts have been established. However, discussions on ROK Navy's roles in countering North Korea's asymmetric threats have been taken place very limitedly. Decision makers and military planners put enormous efforts in getting counter-measures, however, most of the options on the table are systems of Army and Air Force. This is true if one looks at components of Kill-Chain, KAMD, and KMPR. With worsening security environment of the Korean peninsula, it has been said by many commentators that ROK Navy needs to consider expanding its roles in countering against North Korea's asymmetric military threats. They asked ROK Navy to go beyond the mind-set that has confined Navy's roles in deterring North Korean naval threats. That is, ROK Navy should fight 'from the sea' as well as fight 'on the sea.' If ROK Navy begins to think about fight 'from the sea,' there would be many possibilities for the Navy to be a part of countering North Korea's asymmetric military threats. In order to pursue proactive roles in countering North Korea's asymmetric threat, ROK Navy needs to consider various options. Massive missile forces, nuclear-propelled submarines, naval special forces may be some of them. With those measures, ROK Navy would launch massive and decisive attacks from the sea without risking survivability of our forces. Considering North Korean Navy's weakness, it is very probable that sea would be safer place than ground or sky. Expanding ROK Navy's roles and being a proactive deterrent forces against North Korean asymmetric threats would provide very reliable counter-measures to South Korean military. Thus, military planners should think how to take the best advantage of expanded ROK Navy's roles and capabilities against North Korean asymmetric threats.

묘박 중인 선박의 주묘 한계에 관한 연구( I ) (A Study on the Limit of Anchor Dragging for Ship at Anchor( I ))

  • 이윤석;정연철;김세원;윤종휘;배석한;구엔풍
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2005년도 춘계학술대회 논문집
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    • pp.165-171
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    • 2005
  • 태풍이 내습하면 선박은 이를 피해 적절한 묘박지를 선정하여 묘박하게 된다. 묘박 중인 선박은 일단 태풍의 영향권에 들어가면 바람, 파도 및 해${cdot}$조류에 의해 발생되는 외력와 이에 대응하여 묘와 묘쇄에 의한 파주력 및 기관 추진력에 의한 선박의 대응력이 서로 균형을 이룸으로써 주묘되지 않고 안전하게 견딜 수 있다. 본 연구에서는 묘박 중인 선박이 주묘되지 않고 견딜 수 있는 외력의 한계를 이론적으로 분석할 수 있는 방법을 제시하고, 이를 2003년 9월 태풍 매미가 내습했을 당시 진해만에 묘박했던 선박에 적용해봄으로써 그 타당성을 검토하였다.

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Identification of DC21 as a Novel Target Gene Counter-regulated by IL-12 and IL-4

  • Kong, Kyoung-Ah;Jang, Ji-Young;Lee, Choong-Eun
    • BMB Reports
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    • 제35권6호
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    • pp.623-628
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    • 2002
  • The Th1 vs. Th2 balance is critical for the maintenance of immune homeostasis. Therefore, the genes that are selectively-regulated by the Th1 and Th2 cytokines are likely to play an important role in the Th1 and Th2 immune responses. In order to search for and identify the novel target genes that are differentially regulated by the Th1/Th2 cytokines, the human PBMC mRNAs differentially expressed upon the stimulation with IL-4 or IL-12, were screened by employing the differential display-polymerase chain reaction. Among a number of clones selected, DC21 was identified as a novel target gene that is regulated by IL-4 and IL-12. The DC21 gene expression was up-regulated either by IL-4 or IL-12, yet counter-regulated by co-treatment with IL-4 and IL-12. DC21 is a dendritic cell protein with an unknown function. The sequence analysis and conserved-domain search revealed that it has two AU-rich motifs in the 3'UTR, which is a target site for the regulation of mRNA stability by cytokines, and that it belongs to the N-acetyltransferase family. The induction of DC21 by IL-12 peaked around 8-12 h, and lasted until 24 h. LY294002 and SB203580 significantly suppressed the IL-12-induced DC21 gene expression, which implies that PI3K and p38/JNK are involved in the IL-12 signal transduction pathway that leads to the DC21 expression. Furthermore, tissue blot data indicated that DC21 is highly expressed in tissues with specialized-resident macrophages, such as the lung, liver, kidney, and placenta. Together, these data suggest a possible role for DC21 in the differentiation and maturation of dendritic cells regulated by IL-4 and IL-12.

묘박 중인 선박의 주묘 한계에 관한 연구( I ) (A Study on the Limit of Anchor Dragging for Ship at Anchor( I ))

  • 이윤석;정연철;김세원;윤종휘;배석한;구엔풍
    • 한국항해항만학회지
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    • 제29권5호
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    • pp.357-363
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    • 2005
  • 태풍이 내습하면 선박은 이를 피해 적절한 묘박지를 선정하여 묘박하게 된다. 묘박 중인 선박은 일단 태풍의 영향권에 들어가면 바람, 파도 및 해${\cdot}$조류에 의해 발생되는 외력과 이에 대응하여 묘와 묘쇄에 의한 파주력 및 기관 추진력에 의한 선박의 대응력이 서로 균형을 이룸으로써 주묘되지 않고 안전하게 견딜 수 있다. 본 연구에서는 묘박 중인 선박이 주묘되지 않고 견딜 수 있는 외력의 한계를 이론적으로 분석할 수 있는 방법을 제시하고, 이를 2003년 9월 태풍 매미가 내습했을 당시 진해만에 묘박했던 선박에 적용해봄으로써 그 타당성을 검토하였다.

2-(1,3,3-Trimethyl-6-azabicyclo[3,2,1]-oct-6-yl)-4,5-dihydro-1,3-oxazoline(TAO)의 개환이성화중합과 특성평가 (Characteristics and Ring-Opening Isomerization Polymerization of 2-(1,3,3-Trimethyl-6-azabicyclo[3,2,1]-oct-6-yl)-4,5-dihydro-1,3-oxazoline (TAO))

  • 이찬우;정진도
    • 폴리머
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    • 제36권3호
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    • pp.262-267
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    • 2012
  • 할로겐화알킬($PhCH_2Br$, $PhCH_2Cl$, MeI)과 설폰산에스테르(MeOTf)를 개시제로 사용하여 $100^{\circ}C$, 24시간의 반응조건으로 2-(1,3,3-trimethyl-6-azabicyclo[3,2,1]-oct-6-yl)-4,5-dihydro-1,3-oxazoline(TAO)의 중합을 실시, 개시제에 의한 폴리머구조의 영향을 관찰한 결과, 양쪽 개시제 모두 거의 동일한 연쇄이동에서 나타나는 경향과 비슷한 결과를 얻었다. 그러나 개시제에 의한 폴리머의 구조는 설폰산에스테르계 개시제에서는 거의 100% pendant type 폴리머가 생성되는 반면, 할로겐화알킬계 개시제를 사용한 TAO중합은 pendant type 단위와 main chain type의 단위가 소량 생성됨이 확인되어 이것은 구핵성이 높은 할로겐 음이온에 의한 이중이성화중합이 부분적으로 진행되었음을 확인하였으며, 개시제로 Merrifield수지를 사용한 TAO와의 공중합에서는 다량의 단일중합체가 부생되는 그래프트 공중합체가 생성되었다.

북한의 임박한 핵무기 배치대비 국방전략 대개혁 (ROK's defense reform strategy for coping with the emerging North Korea's nuclear weapons.)

  • 김종민
    • Strategy21
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    • 통권41호
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    • pp.208-231
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    • 2017
  • The balance of power in conventional forces between the two Koreas works in favor of the South Korea in the Korea peninsula. But, the balancing mechanism between the two Koreas in asymmetric forces like nuclear and missile forces works absolutely in favor of the North Korea. That's why it should be timely for the ROK military to review existing strategy and revise a new counter strategy against the threat posed by the North Korea's nuclear and missile forces. The ROK military is now developing 4D, KAMD, KILL Chain strategies as means to cope with the North Korea's nuclear and missile threats. Considering efforts and resources invested now, the strategies are expected to be in place in next five or more years. However, approaches to those strategies seem to be rather fragmentary and conceptual than comprehensive and pragmatic. The types of strategies against the North Korea's military threats need to be a deterrence in peace time and a fighting and winning in war time in the Korean theater. But, the most important element in the deterrence strategy is the credibility. This study concludes with an new strategic concept titled "ADAD(Assured Defense, Assured Destruction)" as an alternative to existing strategies to deal with the North Korea's nuclear and missile threats.

AC와 DC 노이즈가 있는 적분기 시스템에서 측정에러의 영향을 감소시키는 스위칭 상태 궤환 제어기의 설계 및 분석 (Design and Analysis of a Switching State Feedback Controller to Reduce the Measurement Error Effect for a Chain of Integrators System under AC and DC Noise)

  • 오상영;최호림
    • 제어로봇시스템학회논문지
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    • 제20권1호
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    • pp.12-17
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    • 2014
  • In this paper, we propose a controller capable of reducing the effect of measurement errors under AC and DC noise. Typically, the control system measures data through a sensor. If sensor noise is included in a controller via the feedback channel, the signal is distorted and the entire system cannot work normally. Therefore, some appropriate action to counter the measurement error effect is essential in the controller design. Our controller is equipped with a gain-scaling factor and a compensator to reduce the effect of measurement error in the feedback signal. Also, we use a switching control strategy to enhance the performance of the controller regarding convergence speed. Our proposed controller can therefore effectively reduce the AC and DC noise of the sensor. We analyze the proposed controller by Laplace transform technique and our control method is verified via MATLAB simulation.

부틸글리시딜에테르와 이산화탄소의 부가반응에 대한 이온성 액체의 촉매 성능 고찰 (Catalytic Performance of Ionic Liquids for the Cycloaddition of Carbon Dioxide and Butyl Glycidyl Ether)

  • 박대원;주혜영;이미경
    • 한국응용과학기술학회지
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    • 제25권4호
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    • pp.469-476
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    • 2008
  • The synthesis of cyclic carbonate from butyl glycidyl ether (BGE) and carbon dioxide was performed in the presence of three different types of ionic liquid : quarternary ammonium salt, alkyl pyridinium salt, and alkylimidazolium salt. Ionic liquids of different alkyl groups ($C_3$, $C_4$, $C_6$ and $C_8$) and anions ($Cl^-$, $Br^-$ and $I^-$) were used for the reaction which was carried out in a batch autoclave reactor at $60{\sim}120^{\circ}C$. The catalytic activity was increased with increasing alkyl chain length in the order of $C_3$ < $C_4$ < $C_6$. But the ionic liquid with longer alkyl chain length ($C_8$) decreased the conversion of BGE because it is too bulky to form an intermediate with BGE. For the counter anion of the ionic liquid catalysts, the BGE conversion decreased in the order $Cl^-$ > $Br^-$ > $I^-$.

위성시스템 강우 감쇠 보상을 위한 ACM 성능 시뮬레이션 (Performance Simulation of ACM for Compensating Rain Attenuation in Satellite Link)

  • 장매향;김수영;백정기;김인겸
    • 한국위성정보통신학회논문지
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    • 제7권3호
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    • pp.8-15
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    • 2012
  • Ku 대역 이상의 고주파수 대역을 사용하는 위성통신 시스템의 링크 성능 저하의 가장 큰 요인인 강우 감쇠를 효과적으로 보상할 수 있는 방법으로 적응형 전송 방식을 들 수 있다. 본 논문에서는 국내 Ka 대역 강우 환경에 적합하도록 개발된 동적 강우 감쇠 모델을 탑재하여 구현된 적응형 강우감쇠 보상 시뮬레이터을 제시한다. 본 논문에서 소개된 시뮬레이터에는 초 단위 강우 감쇠 실측 데이터에 대한 통계치를 바탕으로 추출된 강우 파라미터가 적용된 동적 강우 감쇠 Markov chain 모델이 탑재되어 있다. 또한, 여러 가지 전송 기법들을 구비하여 사용자의 요구 사항에 따른 다양한 시뮬레이션이 가능하도록 하였다. 본 논문에서 는 또한 적응형 전송기법을 이용하여 시뮬레이션한 결과를 고정형 전송기법의 결과와 비교함으로써, 적응형 전송 기법의 활용이 효과적으로 강우 감쇠를 보상할 수 있음을 보였다.