• Title/Summary/Keyword: Homing

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A LOS Rate Estimator for Homing Seekers with 2 Axis Gimbal System (2축 김발 호밍 탐색기를 위한 시선변화율 추정기법)

  • Whang, Ick-Ho;Hwang, Tae-Won
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.12
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    • pp.1024-1030
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    • 2001
  • In this paper, a horizontal LOS(line of sight) rate estimator for conventional sea skimming ASM(anti-ship missile) is proposed. A LOS rate dynamics model for a 2-axis gimbal system and the homing geometry is derived. A new LOS rate estimator is proposed by applying the Kalman filter theory to the LOS rate dynamics model. The proposed filter estimates LOS rates by taking roll motions into account. Simulation results show that the proposed filter produces smaller estimation errors than a conventional method.

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Sensor-based Local Homing Algorithm using Fuzzy Theory (퍼지 이론을 사용한 Sensor-based Local Homing 알고리즘 개발)

  • Bang, S.W.;Lee, J.Y.;Kim, S.D.;Yoo, W.P.;Chung, M.J.
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.387-390
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    • 1993
  • The most important technique for an indoor robot navigation is to find out the direction and the distance from the current location to the destination through the information achieved from the sensor. For this purpose, we suggest sensor-based local homing method which compares the destination sensory data with the current location. As for the sensors, we use the CCD camera and the ultrasonic sensor, and recorded entire 360 degree panoramic data. We match the features of the image data, and the distance and the direction of the matched point will be considered as fuzzy numbers. Through a simple fuzzy arithmetic, we infer the geometric relations between the current location and the destination location.

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Homing Guidance Law for Alleviating Sensitivity to Initial Heading Errors (초기 헤딩오차 민감도 완화 호밍 유도법칙)

  • Lee, Jin-Ik;Jeon, In-Soo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.4
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    • pp.29-35
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    • 2008
  • In this paper, a new guidance law to reduce sensitivity to the initial heading errors is proposed. In order for shaping the input weights over the flight, we introduce the distribution functions expressed in terms of time-to-go and its inverse term. By applying the optimal control theory with the synthesized weights, the homing guidance law is derived. Also the characteristics of the proposed law are examined. Various computer simulations show the good performance of the proposed guidance.

Survey on the IETF Activities for IPv6 Multi-homing (IPv6 멀티홈을 지원하기 위한 IETF 연구 동향)

  • Kim Geonung;Song Byung-Kwen;Ju Yong-Wan;Kim Weon
    • Proceedings of the Korean Information Science Society Conference
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    • 2005.11a
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    • pp.208-210
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    • 2005
  • 장애 극복, 중복, 부하 분산, 서비스 비용, 정책 등의 이유로, IPv6에서 멀티홈(Multi-homing)을 지원하는 연구들이 진행 중이다. 본 논문에서는 현재 진행 중인 멀티홈 지원 방안들을 살펴보고, 특히 이름과 위치 정보를 분리하는 방향으로 진행 중인 연구들 중 대표적인 HIP와 Shim의 방안을 비교한다.

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Homing Navigation based on Path Integration (경로 누적법을 이용한 로봇의 홈 네비게이션 알고리즘)

  • Lee, Ji-Won;Kim, Dae-Eun
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.1057-1058
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    • 2008
  • In this paper, the algorithm and the computer simulation of a effective homing navigation system are presented. it is a combination of Path integration by using population coding and neural network and simple avoidance obstacle algorithm. Also, through the computer simulation, we demonstrated the feasibility of the suggested method.

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The closed-form solution and its approximation of the optimal guidance law (최적유도법칙의 closed-form 해와 근사식)

  • 탁민제;박봉규;선병찬;황인석;조항주;송택렬
    • 제어로봇시스템학회:학술대회논문집
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    • 1992.10a
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    • pp.572-577
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    • 1992
  • In this paper, the optimal homing guidance problem is investigated for the general missile/target models described in the state-space. The closed-form solution of the optimal guidance law derived, and its asymptotic properties are studied as the time-to-go goes to infinity or zero. Futhermore, several approximate solutions of the optimal guidance law are suggested for real-time applications.

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Roll Compensation for Homing Seekers with 2-Axis Gimbal (2축 김발 호밍 탐색기에서의 롤운동 보상)

  • Whang, Ick-Ho
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.1932-1934
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    • 2001
  • In this paper, a horizontal LOS(line of sight) rate estimator for conventional sea skimming ASM(anti-ship missile) is proposed. A LOS rate dynamics model in 2 axis gimbal system and in homing geometry is derived. And a new LOS rate estimator is proposed by applying a Kalman filter theory to the LOS rate dynamics model. The proposed filter can estimate LOS rates with taking roll motions into account. Simulation results show the proposed filter produces smaller estimation errors than a conventional method.

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Trends in Protein Engineering for Gene Targeting: Homing Endonucleases and Zinc Finger Nucleases (유전자 표적화를 위한 단백질공학 연구동향: Homing Endonucleases and Zinc Finger Nucleases)

  • Cheong, Dea-Eun;Kim, Geun-Joong
    • KSBB Journal
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    • v.25 no.3
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    • pp.215-222
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    • 2010
  • Monogenic diseases are resulted from modifications in a single gene of human cells. Because their treatment with pharmacological medicine have a temporary effect, continuous nursing care and retreatment are required. Gene therapy, gene targeting and induced pluripotent stem cell (iPSC) are considered permanent treatment methods of them. In gene therapy, however, retroviral vectors that have potential toxicity caused by random insertion of harmful virus are used as vehicles for transferring genetic materials. On the other hand, gene targeting could replace and remove the modified gene though homologous recombination (HR) induced by site-specific endonucleases. This short review provides a brief overview on the recently tailored endonucleses with high selectivity for HR.

Composite Guidance Law for Impact Angle Control of Passive Homing Missiles (수동 호밍 유도탄의 충돌각 제어를 위한 복합 유도법칙)

  • Park, Bong-Gyun;Kim, Tae-Hun;Tahk, Min-Jea;Kim, Youn-Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.1
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    • pp.20-28
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    • 2014
  • In this paper, based on the characteristics of proportional navigation, a composite guidance law is proposed for impact angle control of passive homing missiles maintaining the lock-on condition of the seeker. The proposed law is composed of two guidance commands: the first command is to keep the look angle constant after converging to the specific look angle of the seeker, and the second is to impact the target with terminal angle constraint and is implemented after satisfying the specific line of sight(LOS) angle. Because the proposed law considers the seeker's filed-of-view(FOV) and acceleration limits simultaneously and requires neither time-to-go estimation nor relative range information, it can be easily applied to passive homing missiles. The performance and characteristics of the proposed law are investigated through nonlinear simulations with various engagement conditions.

Homing and Restorative Effects of Bone Marrow-Derived Mesenchymal Stem Cells on Cisplatin Injured Ovaries in Rats

  • Liu, Jiabin;Zhang, Haiying;Zhang, Yun;Li, Nan;Wen, Yuku;Cao, Fanglei;Ai, Hao;Xue, Xiaoou
    • Molecules and Cells
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    • v.37 no.12
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    • pp.865-872
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    • 2014
  • Premature ovarian failure (POF) is a long-term adverse effect of chemotherapy treatment. However, current available treatment regimens are not optimal. Emerging evidence suggests that bone marrow-derived mesenchymal stem cells (BMSCs) could restore the structure and function of injured tissues, but the homing and restorative effects of BMSCs on chemotherapy injured ovaries are still not clear. In this study, we found that granulosa cell (GC) apoptosis induced by cisplatin was reduced when BMSCs were migrated to granulosa cells (GCs) in vitro. Chemotherapy-induced POF was induced by intraperitoneal injection of cisplatin in rats. BMSCs labeled with enhanced green fluorescent protein (EGFP) were injected into the rats via the tail vein to investigate the homing and distribution of BMSCs in vivo. The number of BMSCs in the ovarian hilum and medulla was greater than in the cortex, but no BMSCs were found in the follicles and corpus lutea. In addition, the BMSCs treatment group's antral follicle count and estradiol levels increased after 30 days, compared with the POF group. Hence, our study demonstrates that intravenously delivered BMSCs can home to the ovaries, and restore its structure and function in POF model rats.