• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1822-1825
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• 2003

A practical range estimator based on the robust Kalman filter is proposed to solve the range estimation problem for surface to air missile(SAM) homing guidance. Apart from the previous works based on the extended Kalman filter(EKF) with bearing only measurement, the proposed scheme makes use of line-of-sight(LOS) rate to ensure the fast convergency at long-range. In this reason, the robust Kalman filter is considered to deal with LOS rate measurement error. The recursive linear structure of proposed filter is easy to implement and make it possible to reduce computational burdens. Moreover, it shows good estimation performance without specific guidance law such as oscillation proportional navigation guidance(OPNG).

• International Journal of Control, Automation, and Systems
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• v.3 no.3
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• pp.486-492
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• 2005

A practical recursive WLS (weighted least squares) algorithm is proposed to estimate relative range using LOS (line-of-sight) information for ASM (anti-ship missile) application. Apart from the previous approaches based on the EKF (extended Kalman filter), to ensure good convergence properties in long range engagement situations, the proposed scheme utilizes LOS rate measurements instead of conventionally used LOS angle measurements. The estimation error property for the proposed filter is investigated and a simple error compensator is devised to enhance its estimation error performances. Simulation results indicate that the proposed filter produces very accurate range estimates with extremely small computations.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.170-175
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• 1998

Transporting a large table using multiple robotic agents requires at least two group behaviors of homing and herding which are to bo coordinated in a proper sequence. Existing GP methods for multi-agent learning are not practical enough to find an optimal solution in this domain. To evolve this kind of complex cooperative behavior we use a novel method called fitness switching. This method maintains a pool of basis fitness functions each of which corresponds to a primitive group behavior. The basis functions are then progressively combined into more complex fitness functions to co-evolve more complex behavior. The performance of the presented method is compared with that of two conventional methods. Experimental results show that coevolutionary fitness switching provides an effective mechanism for evolving complex emergent behavior which may not be solved by simple genetic programming.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1736-1737
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• 2011

This paper deals with the problem of precise impact angle control of an actual homing missile guided by biased proportional navigation (BPN). To do this, the BPN guidance loop including dynamic lag is modeled as the confluent hyper-geometric differential equation and its analytic solution is derived. Based on the solution, a systematic way to determine the bias constant is newly devised. Different from the existing BPN solution obtained by ignoring the dynamic lag, the proposed one can exactly describe the behavior missile before target interception. hence it is drastically improved the angle constrained terminal guidance performance.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.610-612
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• 2002

현재 인터넷은 IPv4주소 고갈로 인해 종래의 클래스(class)별 주소의 분배와 사용을 지양하고 클래스 없는 CIDR(Classless InterDomain Routing)〔1〕방식을 채택하고 있다. 본 논문에서는 라우터의 개발 및 성능에 영향을 미치는 라우팅 엔트리의 분포와 특성을 다음의 세가지 관점에서 분석하였다. 그리고 분석에 사용된 데이터는 백본용 라우터의 라우팅 테이블이다. 첫째, 현재 인터넷에서 CIDR 방식에 따른 서브넷팅(Subnetting)과 슈퍼넷팅(Supernetting)〔2〕〔3〕정도를 분석하였으며 둘째, 현재 포워딩 테이블(Forwarding Table)내의 불필요한 포워딩 엔트리(Forwarding Entry)들이 차지하는 구성비를 조사하였다. 마지막으로는 멀티홈밍(Multi-homing)이 포워딩 테이블의 크기에 미치는 영향을 분석하였다. 조사에 의하면 MAE-East와 MAE-West〔4〕와 같은 백본(Backbon) 라우터의 경우에 A클래스는 8에서 26비트까지, B클래스는 14비트에서 27비트까지 그리고 C클래스는 17비트에서32비트까지 서브넷팅과 슈퍼넷팅이 되어있다. 또한 불필요한 포워딩 엔트리는 전체 엔트리의약 1%를 차지하고 있으며, 멀티홈밍 엔트리는 약 5%를 차지하는 것으로 확인되었다.

• Journal of Environmental Impact Assessment
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• v.18 no.3
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• pp.123-129
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• 2009

In Korea the population of breeding house swallow is continuously decreasing. In this regard this study was conducted to find out the overall population trend during 2001-2005. The areas of urban and rural sites were separated to estimate population. Also the sites in Yangpyung areas were chosen to compare population density between two sites during Mar-Aug, 2006. The house swallow had two breeding periods and I tried to correlated amount of days of incubation and number of eggs in the nest. After egg hatching the homing behavior also was estimated assuming lack of foods takes longer to bring foods back to the nest. This study signified that a long term study should be conducted for population change and spring arrival time due to climate change in Korea.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.349-353
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• 2007

유비쿼터스 네트워크환경에서 멀티호밍 기술은 무선 단말이 두 개 이상의 경로를 통해 인터넷에 연결 될 수 있는 기술로써 보다 효율적인 이동성 지원, 다중 경로를 이용한 신뢰성 보장 그리고 사용자를 위한 다양한 QoS(Quality of Service)를 제공할 수 있는 기술이다. 하지만 현재 IP 계층에서의 멀티호밍 기술은 멀티호밍의 필요성과 유용성에대한 정의 단계이며 이 기술을 지원하는 적합한 메커니즘이 없다. 따라서 본 논문에서는 IP 계층에서의 멀티호밍을 지원하기 위하여 신호의 세기, 데이터 전송률, 대역폭 사용률 그리고 트래픽의 특성과 같은 네트워크의 다양한 요소들을 분석하고 그에 따른 최적의 경로를 설정 할 수 있는 메커니즘을 제안하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.436-439
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• 2008

멀티호밍 기술은 유비쿼터스 네트워크에서 중요한 기술 중 하나이며 이를 이용한 다양한 네트워크 서비스 시나리오들이 제안되고 있다. 따라서 멀티호밍 환경에서 가장 중요한 경로의 설정 방법, 관리 그리고 대체 경로 설정에 관한 연구가 필요하다. 본 논문에서는 기존 가용대역폭 측정방법을 이용하여 각각의 경로의 가용대역폭을 측정하여 단말이 가지는 여러 경로 중 가장 최상의 경로를 결정하는 메커니즘을 제안 한다. 이를 위해 기존의 가용대역폭 측정방법들이 가지는 측정 속도의 문제와 정확한 가용대역폭의 계산을 위한 새로운 알고리즘을 제시하고 이를 이용 단말에서 실시간으로 수신측과 연결되어 있는 경로들에 대한 네트워크의 상태를 파악하여 최적의 경로 설정 메커니즘을 제안한다.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.125-132
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• 1993

When a mobile robot moves around autonomously without man-made landmarks, it is essential to recognize the placement of surrounding objects especially for current position estimation, obstacle avoidance, or homing into the work station. In this paper, we propose a novel approach to recognize the floor paln for indoor mobile robot navigation using ultrasonic time-of-flight method. We model the floor plan as a collection of polygonal plane objects and recognize the floor plan by locating edges and vertices of the objects. The direction is estimated by the patterns of transmission beam and reception sensitivity of the ultrasonic transducer, and the distance is estimated by the correlation detection method. We show the validity of the proposed approach through experimental results and discuss the resolution and the accuracy of the estimation of direction and distance.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.245-248
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• 1996

This paper suggests a new concept for missile guidance control, called linearized common curvature guidance law that enhances the probability to kill a target. The proposed guidance system is composed of two switching modes; one for the midcourse guidance and the other for the terminal guidance, which is switched by a specified critical value (.epsilon.). And the system and the commands are formulated and its simulations are provided in comparison with the conventional commanded line of sight guidance algorithm. Miss distance and angle of attack are denoted as performance of parameters. This new concept, common curvature guidance algorithm, revises the navigation guidance and accompanies, various considerations.