• Title/Summary/Keyword: Target pointing

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Analysis on the Orbit Prediction Accuracy of the Image Collection Planning for KOMPSAT-2 (아리랑위성 2호 영상촬영계획 궤도예측 정밀도 분석)

  • Jung, Ok-Chul;Kim, Hae-Dong;Chung, Dae-Won
    • Aerospace Engineering and Technology
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    • v.7 no.1
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    • pp.223-228
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    • 2008
  • In order to acquire the images requested by users, it is very important to calculate mission schedule parameters such as imaging execution time and attitude tilt angle accurately. These parameters are based on orbit prediction. This paper describes the accuracy of orbit propagation for image planning. The orbit prediction data from PSS and MAPS has a certain discrepancy due to different orbit propagator. It is necessary for mission planner to confirm this value during mission planning phase. The pointing error which means the difference between target center and real image received is calculated and analyzed using KOMPSAT-2 image data.

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The strategy to catch more early light curves of supernovae

  • Hwang, Jeeun;Im, Myungshin;Paek, Gregory S.H.
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.71.3-72
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    • 2021
  • The Intensive Monitoring Survey of Nearby Galaxies (IMSNG) is a high cadence observation program monitoring nearby galaxies at < 50 Mpc with high probabilities of hosting supernovae (SNe). The current number of main IMSNG targets is 60, but with new wide-field facilities joining IMSNG, there is a possibility of increasing the likelihood of catching the early light curves of SNe among galaxies in the vicinity of the main targets. To test the feasibility of the expansion of the sample galaxies, we examine how much the probability of catching SNe increases by adjusting the field of view of the RASA36 telescope which is one of the IMSNG facilities with a large field of view of 6.25 deg2. We calculate supernova rates (SNRs) of galaxies within the FoV that contains main IMSNG galaxies from the stellar mass and star formation rate of the galaxies. Based on the SNRs of these galaxies, we find the best pointing of the telescope towards the highest SNR region. As a result, we present improved total SNR, with respect to the ordinary pointing on average where the IMSNG main target is placed at the center of FoV. The actual observation should be followed to test the effect of this strategy.

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Geometric analysis of Missile applied in Frenet-Serret formula & Missile guidance applied in Fuzzy Control (Frenet-Sorret formula를 적용한 미사일의 기하학적 분석과 퍼지제어를 이용한 미사일유도)

  • Park, Sung-Chul;Hwang, Eun-Ju;Park, Mignon
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.632-634
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    • 2005
  • In this paper, The Frenet-Serret formula of classical geometric curve theory with the concept of a missile pointing velocity vector are used to analyze and design a missile guidance law. The capture capability of this guidance law is qualitatively studied by comparing the rotations of the velocity vectors of missile and target relative to the line of sight vector. when fuzzy Table look-up theory applied in target-missile distance & angle displacement, this research. It's performance is better then classical research.

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A Study on a Tracking Method of Telemetry Signal using Self-Slaving (Self-Slaving을 이용한 원격측정 신호추적 기법 연구)

  • Lee, Sung-Pil
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.3
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    • pp.50-57
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    • 2008
  • A telemetry ground station has a highly directional, parabolic tracking antenna to receive a weak telemetry signal from a target at a distance. The tracking antenna with narrow beam-width normally uses the auto-track method for the target tracking. This paper presents several issues in the auto-track method and introduces a new tracking method using Self-Slaving technique. Self-Slaving means that the tracking antenna is slaved to not data measured by RADAR but GPS/INS informations received by the telemetry system for pointing. The Self-Slaving method shows good performance in comparison with auto-track method.

A decoupling controller design for the seeker scan loop with a spin-stabilized platform (자전 안정화형 탐색기 주사루프의 비연성 제어기 설계)

  • 유인억;이상정
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.5
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    • pp.35-41
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    • 1998
  • This paper presents a decoupling controller of the missile seeker scan loop with a spin-stabilized platform. A precise seeker motion with respect to the scan command is essential for the higher acquisition probability of the target. As the seeker scan loop is a deeply cross-coupled two input two output system, an accurate pointing or scanning for each axis to the target is very difficult, even though provided with the help of a high performance controller. When a decoupling control is applied to the seeker scan loop, the cross-coupling between two axes can be reduced to a remarkable amount. As a low order of controller is required for the real time operation, a PI controller with decoupling filter is suggested and compared with other controllers. A linearized dynamic model of seeker scan loop is used and validated through the comparison of experimental results of step responses.

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Human Spatial Cognition Using Visual and Auditory Stimulation

  • Yu, Mi;Piao, Yong-Jun;Kim, Yong-Yook;Kwon, Tae-Kyu;Hong, Chul-Un;Kim, Nam-Gyun
    • International Journal of Precision Engineering and Manufacturing
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    • v.7 no.2
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    • pp.41-45
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    • 2006
  • This paper deals with human spatial cognition using visual and auditory stimulation. More specially, this investigation is to observe the relationship between the head and the eye motor system for the localization of visual target direction in space and to try to describe what is the role of right-side versus left-side pinna. In the experiment of visual stimulation, nineteen red LEDs (Luminescent Diodes, Brightness: $210\;cd/^2$) arrayed in the horizontal plane of the surrounding panel are used. Here the LEDs are located 10 degrees apart from each other. Physiological parameters such as EOG (Electro-Oculography), head movement, and their synergic control are measured by BIOPAC system and 3SPACE FASTRAK. In the experiment of auditory stimulation, one side of the pinna function was distorted intentionally by inserting a short tube in the ear canal. The localization error caused by right and left side pinna distortion was investigated as well. Since a laser pointer showed much less error (0.5%) in localizing target position than FASTRAK (30%) that has been generally used, a laser pointer was used for the pointing task. It was found that harmonic components were not essential for auditory target localization. However, non-harmonic nearby frequency components was found to be more important in localizing the target direction of sound. We have found that the right pinna carries out one of the most important functions in localizing target direction and pure tone with only one frequency component is confusing to be localized. It was also found that the latency time is shorter in self moved tracking (SMT) than eye alone tracking (EAT) and eye hand tracking (EHT). These results can be used in further study on the characterization of human spatial cognition.

Cinobufacin Suppresses Cell Proliferation via miR-494 in BGC-823 Gastric Cancer Cells

  • Zhou, Rong-Ping;Chen, Gang;Shen, Zhi-Li;Pan, Li-Qun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1241-1245
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    • 2014
  • Cinobufacin is used clinically to treat patients with many solid malignant tumors. However, the mechanisms underlying action remain to be detailed. Our study focused on miRNAs involved in cinobufacin inhibition of GC cell proliferation. miRNA microarray analysis and real time PCR identified miR-494 as a significant cinobufacin-associated miRNA. In vivo, ectopic expression of miR-494 inhibited the proliferation and induced apoptosis of BGC-823 cells on CCK-8 and flow cytometry analysis. Further study verified BAG-1 (anti-apoptosis gene) to bea target of miR-494 by luciferase reporter assay and Western blotting. In summary, our study demonstrated that cinobufacin may inhibit the proliferation and promote the apoptosis of BGC-823 cells. Cinobufacin-associated miR-494 may indirectly be involved in cell proliferation and apoptosis by targeting BAG-1, pointing to use as a potential molecular target of cinobufacin in gastric cancer therapy.

Effects of the Target Size and the Number of Targets for Pointing Performance on Small Display (소형표시창에서 타겟의 크기와 개수가 포인팅성능에 미치는 영향)

  • 박정순
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2003.11a
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    • pp.51-55
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    • 2003
  • 소형 표시창에서 펜과 커서키를 이용한 타겟 포인팅 성능을 비교하기 위하여 두 가지 실험이 수행되었다. 첫 번째 실험에서 우리는 서로 다른 타겟 크기에서 두 가지 입력방법에 의한 참여자의 타겟 포인팅 성능을 조사하였다. 타겟의 크기가 5미리 보다 작을 경우 펜입력이 키를 기본으로 하는 입력보다 더 에러가 많지만 타겟 크기가 5미리일 때 에러율이 키입력과 같은 수준으로 감소한다는 것을 발견했다. 두 번째 실험에서 우리는 타겟의 개수가 미치는 영향을 조사하였다. 그 결과 타겟의 크기가 5미리일 때 타겟의 거리가 3단계의 경로길이를 초과할 경우 펜입력이 키입력보다 더 빨리 타겟을 포인팅할 수 있다는 것을 알았다.

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Understanding EGFR Signaling in Breast Cancer and Breast Cancer Stem Cells: Overexpression and Therapeutic Implications

  • Alanazi, Ibrahim O;Khan, Zahid
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.2
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    • pp.445-453
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    • 2016
  • Epidermal growth factor receptors (EGFRs/HERs) and downstream signaling pathways have been implicated in the pathogenesis of several malignancies including breast cancer and its resistance to treatment with chemotherapeutic drugs. Consequently, several monoclonal antibodies as well as small molecule inhibitors targeting these pathways have emerged as therapeutic tools in the recent past. However, studies have shown that utilizing these molecules in combination with chemotherapy has yielded only limited success. This review describes the current understanding of EGFRs/HERs and associated signaling pathways in relation to development of breast cancer and responses to various cancer treatments in the hope of pointing to improved prevention, diagnosis and treatment. Also, we review the role of breast cancer stem cells (BCSCs) in disease and the potential to target these cells.

Effect of System Instability Factors in a Bistatic MTI Radar Using Pulse Chasing Scan Method (펄스 체이싱 스캔 방식을 이용한 바이스태틱 MTI 레이더에서 시스템 불안정 요소들의 영향)

  • Yang, Jin-Mo;Han, Il-Tak;Lee, Yong-Suk;Lee, Min-Joon;Kim, Whan-Woo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.3
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    • pp.299-311
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    • 2011
  • In this paper, we have identified the system instability factors in a bistatic radar system using pulse chasing and considered their effects on the bistatic receiver's MTI(Moving Target Indication) improvement performance. The pulse chasing is a scan method that searchs a restricted area on the transmit pulse-to-pulse basis and the MTI filter is a signal processing that separates a target from some kinds of interferences such as clutter using small number of transmit pulses. Ideal MTI processing performance, e.g., clutter attenuation and improvement, has been limited by the property of the clutter itself, however, the MTI performance in a proposed bistatic receiver configuration could be affected by the receiving beam pointing error during pulse chasing scanning. Also, for the bistatic receiver, we have defined other system instability factors, which result from the time synchronization error, COHO's phase error, the frequency/phase synchronization error, and have analyzed their effects on the system performance improvement.