• Title/Summary/Keyword: agency function

Search Result 849, Processing Time 0.1 seconds

Omni Scanning DPCA using Two Passive Antennas with Vertical Separation

  • Kim Man-Jo;Kho Bo-Yeon;Yoon Sang-Ho
    • Korean Journal of Remote Sensing
    • /
    • v.22 no.3
    • /
    • pp.229-234
    • /
    • 2006
  • In tactical theater, it is crucial to detect ground moving targets and to locate them precisely. This problem can be resolved by using SAR (Synthetic Aperture Radar) sensors providing GMTI (Ground Moving Target Indication) capability. In general, to implement a robust GMTI sensor is not simple because of the strong competitions between target signals and clutter signals from the ground, and low speed of moving targets. Contrary to the case that a delay canceller is mostly suitable for ground surveillance radars, DPCA (Displaced Phase Centered Antenna) or STAP (Space Time Adaptive Processing) techniques have been widely adapted for GMTI function of modern airborne radars. In this paper, a new scheme of DPCA using two passive antennas with vertical separation is proposed, which also provides good clutter cancellation performance. The proposed scheme realizes full azimuth coverage for DPCA operation on an airborne platform, which is impossible with classical DPCA configuration. Simulations using various conditions have been performed to validate the proposed scheme, and the results are acceptable.

An Investigation of the Environment of Some Aromatic Alcohol Solubilized Aqueous Ionic Micellar Solutions by Proton Magnetic Resonance Spectroscopy

  • Chung, Jong-Jae;Kang, Jung-Bu;Lee, Kyung-Hee;Seo, Byung-Il
    • Bulletin of the Korean Chemical Society
    • /
    • v.15 no.3
    • /
    • pp.198-204
    • /
    • 1994
  • Chemical shifts in aqueous sodium dodecylsulfate(SDS) micellar solution solublizing phenol, catechol, resorcinol, hydroquinone have been measured to investigate solubilization properties. Proton nuclear magnetic resonance frequencies of solubilizates as well as those of the ${\alpha}$-methylene, middle methylene and terminal methyl of SDS shift linearly as a function of solubilizate concentration. From the plots of observed chemical shift (v) vs solubilizate concentration, slope (a) and solubilizate free chemical shift ($v_0$) are obtained. They are very informative to solubilization site of the systems. Catechol and phenol solubilized SDS and catechol solubilized dodecylpyridinium chloride(DPC), dodecyltrimethylammonium bromide(DTAB) systems are studied using the same method to compare head group effect and middle methylene proton signal splitting. It is proposed that phenol and catechol are inserted into micellar interior and the number of methylenes assigned to the higher field peaks is 5.0${\pm}$0.5.

Design of Real-Time Tracking Filter Function for False Target Elimination (거짓 표적 실시간 제거를 위한 추적 필터 기능 설계)

  • Jeong-Seok Kim;Chae-Hyeon Lim;Dae-Yeon Kim
    • Proceedings of the Korean Society of Computer Information Conference
    • /
    • 2023.07a
    • /
    • pp.565-566
    • /
    • 2023
  • 적외선 영상에서 정확하게 표적을 포착하기 위해서는 수많은 거짓 표적과 참표적을 실시간으로 구별하고, 최종적으로 참 표적 하나만을 추적 할 수 있어야 한다. 본 논문에서는 추적 게이트의 이동거리 및 이동 방향을 실시간 감시하여 추적 게이트의 이상 움직임 유무를 확인하고, 추적 필터가 설정한 임계값 대비 높은 수치로 이동하거나, 한 방향이 아닌 다양한 방향으로 움직일 경우 해당 게이트를 신속하게 제거하여 거짓 표적에 대한 추적을 방지하도록 하였다. 또한 추적 게이트 이동 거리 및 확장 크기를 동적으로 조절함으로써 표적의 크기 변화와 표적의 움직임에 강인하게 추적 필터가 동작 되도록 설계하였다.

  • PDF

Development of ESAD with Flight Environment Sensing Function and Sled Test Method for Function Verification (비행환경 감지 기능을 보유한 ESAD 개발 및 기능 확인을 위한 슬레드 시험 방안)

  • Hanseong Jo
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.26 no.3
    • /
    • pp.273-280
    • /
    • 2023
  • Recently electronic safety and arming device(ESAD) has attracted increasing attention due to its design flexibility. However, ESAD can be armed unintentionally due to a malfunction of an external device or interface. Thus ESAD needs an internally generated arming signal independent from the external device. In this paper, a new sensor-hybrid ESAD(SHESAD) with a flight environment sensing function for generating arming signal internally is proposed and a sled test based method is also suggested for evaluating its functions. Through the test results, the operability of the flight environment sensing function was confirmed. Also, it is shown that the proposed test method is suitable for verification of ESAD with the flight environment sensing function.

Computing Coarser Observation Ffunctions Using Control-Compatible States of Supervisor

  • Cho, Hangju
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1993.10a
    • /
    • pp.318-323
    • /
    • 1993
  • The paper discusses the problem of computing coarser observation functions in supervisory control of discrete event systems. It is shown that when a supervisor that realizes a given language L has certain properties, L-realizability of a coarser observation function is equivalent to control-compatibility of the states in some subsets of the state space of the supervisor. This characterization is then used to devise an iterative procedure of computing coarser L-realizable observation functions, where supervisor reduction and L-realizability verification of an observation function are performed at each iteration.

  • PDF

Designing observation functions in supervisory control

  • Cho, Hangju
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1990.10a
    • /
    • pp.523-528
    • /
    • 1990
  • This paper discusses the problem of designing an observation function as coarsest as possible in supervisory control of discrete event dynamic systems. Some algebraic properties of two sets consisting of observation functions for which the given desirable behavior is realizable are investigated:these sets with a partial ordering turn out not to possess largest elements. Two natural methods of obtaining an observation function, which is frequently coarser than the identity mapping, are also presented. An example illustrates the use of these methods.

  • PDF

Proline Metabolism in Neurological and Psychiatric Disorders

  • Yao, Yuxiao;Han, Weiping
    • Molecules and Cells
    • /
    • v.45 no.11
    • /
    • pp.781-788
    • /
    • 2022
  • Proline plays a multifaceted role in protein synthesis, redox balance, cell fate regulation, brain development, and other cellular and physiological processes. Here, we focus our review on proline metabolism in neurons, highlighting the role of dysregulated proline metabolism in neuronal dysfunction and consequently neurological and psychiatric disorders. We will discuss the association between genetic and protein function of enzymes in the proline pathway and the development of neurological and psychiatric disorders. We will conclude with a potential mechanism of proline metabolism in neuronal function and mental health.

A Study on Spotlight SAR Image Formation by using Motion Measurement Results of CDGPS (CDGPS의 요동 측정 결과를 이용한 Spotlight SAR 영상 형성에 관한 연구)

  • Hwang, Jeonghun;Ko, Young-Chang;Kim, So-Yeon;Kwon, Kyoung-Il;Yoon, Sang-Ho;Kim, Hyung-Suk;Shin, Hyun-Ik
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.21 no.2
    • /
    • pp.166-172
    • /
    • 2018
  • To develop and evaluate the real-time SAR(Synthetic Aperture Radar) motion measurement system, true antenna phase center(APC) positions during SAT(Synthetic Aperture Time) are needed. In this paper, CDGPS(Carrier phase Differential Global Positioning System) post processing method is proposed to get the true APC position for spotlight SAR image formation. The CDGPS position is smoothed to remove high frequency noise which exists inherently in the carrier phase measurement. This paper shows smoothed CDGPS data is enough to provide the true APC for high-quality SAR image formation through motion measurement result, phase error estimation and IRF(Impulse Response Function) analysis.

Differentiation potential of canine mesenchymal stem cells on hydrogel scaffold-based three-dimensional environment (하이드로젤 지지체 기반 3차원 환경에서 개 간엽줄기세포의 분화능 분석)

  • Gu, Na-Yeon;Park, Mi Jeong;Lee, Jienny;Byeon, Jeong Su;Jeong, Da-Un;Cho, In-Soo;Cha, Sang-Ho
    • Korean Journal of Veterinary Research
    • /
    • v.58 no.4
    • /
    • pp.211-217
    • /
    • 2018
  • Mesenchymal stem cells (MSCs) are useful candidates for tissue engineering and cell therapy. Physiological cell environment not only connects cells to each other, but also connects cells to the extracellular matrix that provide mechanical support, thus exposing the entire cell surface and activating signaling pathways. Hydrogel is a polymeric material that swells in water and maintains a distinct 3-dimensional (3D) network structure by cross linking. In this study, we investigated the optimized cellular function for canine adipose tissue-derived MSCs (cAD-MSCs) using hydrogel. We observed that the expression levels of Ki67 and proliferating cell nuclear antigen, which are involved in cell proliferation and stemness, were increased in transwell-hydrogel (3D-TN) compared to the transwell-normal (TN). Also, transforming growth factor-${\beta}1$ and SOX9, which are typical bone morphogenesis-inducing factors, were increased in 3D-TN compared to the TN. Collagen type II alpha 1, which is a chondrocyte-specific marker, was increased in 3D-TN compared to the TN. Osteocalcin, which is a osteocyte-specific marker, was increased in 3D-TN compared to the TN. Collectively, preconditioning cAD-MSCs via 3D culture systems can enhance inherent secretory properties that may improve the potency and efficacy of MSCs-based therapies for bone regeneration process.

Design Technique for Wide Swath SAR TOPS imaging Mode (광역관측을 위한 영상레이더 TOPS 모드 설계 기법)

  • Kim, Se-Young;Sung, Jin-Bong;Yi, Dong-Woo;Shim, Sang-Heun
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.43 no.5
    • /
    • pp.466-471
    • /
    • 2015
  • In this paper, the design technique of the wide swath TOPS(Terrain Observation by Progressive Scan) imaging mode is introduced. The TOPS mode overcomes the scalloping limitations imposed by ScanSAR mode by steering the antenna pattern along track direction during the acquisition of a burst. This paper reports the operation concept of TOPS imaging and mode design result to extract the SAR operational parameters. Finally, several analyzed results such as IRF(Impulse Response Function), NESZ(Noise Equivalent Sigma Zero) and DTAR(Distributed Target Ambiguity Ratio) are presented.