• 한국통신학회논문지
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• 제33권12A호
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• pp.1217-1224
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• 2008

갈릴레오 위성시스템의 정확한 위치 확인을 위해서는 기본적으로 정화한 반송파 추적이 이루어져야 한다. 주파수 오차를 추적하기 위한 FLL은 전파 도달 시간의 변화를 발생시키는 동적 음력에 강인하지만 정확한 반송파 추적이 어렵다. 반면 위상 오차를 추적하기 위한 PLL은 정확한 반송파 추적이 가능하지만 동적음력에 약하고 높은 동적음력에서 반송파 추적성능이 저하된다. 본 논문에서는 갈릴레오 L1F 신호에서 높은 동적응력에서도 정확한 반송파 추적이 가능하도록 FLL과 PLL의 상호 보완적인 운용과 FLL지원의 PLL 루프필터를 적용한 반송파 추적루프를 설계하였으며, 모의실험을 통하여 제안한 기법의 성능을 입증하였다.

• 제어로봇시스템학회논문지
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• 제5권3호
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• pp.275-280
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• 1999

This paper presents a disturbance accommodating sliding mode control for a quarter-car active suspension using an electro-hydraulic actuator. The electro-hydraulic actuator model is nonlinear and uncertain. The hardware constrains on the actuator prevent high gain in a sliding mode control, which deteriorates the force tracking performance. DAC(Disturbance Accommodating Control) is combined with the sliding mode control to improve the tracking performance. DAC observer estimates the pressure due to the actuator uncertainty. The additional control is designed to compensate the estimated pressure. Simulation results show the improved tracking performance with the Proposed control methods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.312-314
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• 2006

This paper describes performance of the modified gain scheduling controller by speed control of a DC motor. The modified gain scheduling controller can perform tracking at more than one equilibrium points. The modified gain scheduling controller which considers transient response according to added zero shows better result of tracking performance than the unmodified gain scheduling controller shows.

• 대한인간공학회지
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• 제19권2호
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• pp.47-61
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• 2000

To study the characteristic of the weight center control of humans, the tracking control capability of circular and wave motion by weight center movement was conducted by using the force platform. The control performance(the integrated value of the $|Object\;value(X)-Control\;Value(Y)|^{2}$) and control trace record was used to evaluate the individual performance characteristics. The size of the population for this study was 73, which consisted of engineering students, students majoring in taekwondo, students majoring in dance, all of which were in their twenties, and also people in their sixties. The results of this study indicate that the weight center control characteristics of humans can be represented by the evaluation method and values. People who were capable of tracking the object did not stop nor overshot the objective. In addition, habits or training characteristics and aging seemed to influence the performance of the subjects. In the future, development of different objectives for weight center control could be used to determine the severity of the disease of the subject and the effects of the treatment.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1040-1043
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• 1996

The accuracy of the servo control in CNC system has a great influence on the duality of machine product. Tracking performance of the servo control is deteriorated mainly by the time delay of the servo system and the inertia of the work table or bed. Contouring errors occur in every interpolation steps by the effect of the tracking performance. In this paper, $H_{\infty}$ two-degree-of-freedom(TDF) controller is designed for improvement to improve the tracking performance. The designed controller is applied 3-axis machining center model and the cutting accuracy is simulated in case of corner cutting, circular and involute interpolation. Simulation results show that $H_{\infty}$ TDF controller designed in this paper has a good effect to improve tracking performance in CNC system.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.427-430
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• 2002

This paper presents on contamination performance of polymeric outdoor insulator with different contaminant accumulation. The ESDD (equivalent salt deposit density), tracking resistance and clean-fog test were performed to investigate the characteristics of contamination performance on polymeric outdoor insulator. Furthermore, we evaluated together with the porcelain samples for its comparison. It is found that ESDD of polymeric and porcelain insulator depends on the installation position. This surface accumulation of contaminant lead to the loss of surface hydrophobicity, expecially upper shed part of polymeric insulator. In addition, the effect of an artificial contaminant on the tracking resistance by inclined-plane method and leakage suppression ability under clean fog was surveyed. The time of tracking failure did not appear to change significantly with a much contaminant accumulation, while leakage current under clean-fog increased.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.26-29
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• 2001

In a target tracking problem the radar glint noise has non-Gaussian heavy-tailed distribution and will seriously affect the target tracking performance. In most nonlinear situations an Extended Robust Kalman Filter(ERKF) can yield acceptable performance as long as the noises are white Gaussian. However, an Extended Robust $H_{\infty}$ Filter (ERHF) can yield acceptable performance when the noises are Laplacian. In this paper, we use the Interacting Multiple Model(IMM) estimator for the problem of target tracking with glint noise. In the IMM method, two filters(ERKF and ERHF) are used in parallel to estimate the state. Computer simulations of a real target tracking shows that hybrid filter used the IMM algorithm has superior performance than a single type filter.

• 전자공학회논문지A
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• 제33A권3호
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• pp.1-9
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• 1996

in this paper, we analyzed CDD-DLL code tracking loop for tracking of direct-sequence spread-spectrum signals in a multipath fading channel. The multipath fading channel is modeled as two-ray rayleigh fading channel which is well applicable in a land mobile communication environments. We use trackin jitter variance and mean-time-to-lose-lick as performance measures. From the numerical resutls, it is shown that the effect of multipath fading decreases as SNR/bit increases. Also it is shown that CDD-DLL provides superior jitter performance compared with noncoherent DLL and jitter performance improvement is more significant for a two-ray rayleigh fading channel than an AWGN channel.

• 한국전자파학회논문지
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• 제27권10호
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• pp.900-908
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• 2016

본 논문에서는 일반적인 3채널 구조의 모노펄스수신기와 대비해서 비용, 크기, 무게 및 소모전력 측면에서 유리한 단일채널 구조의 모노펄스수신기를 적용한 추적시스템에 관한 연구를 진행하였다. 안테나, 모노펄스수신기, 구동체, RF 신호처리기 및 전원분배기를 제작 및 통합하여 단일채널 모노펄스시스템을 구현한 후, 지향오차각 산출정확도와 포인팅 손실을 측정하여 기본 추적성능을 확인하였다. 그리고 야외환경에서 실제 이동하는 목표물에 대한 추적성능을 검증하였다. 시험결과 분석을 통해 단일채널 모노펄스시스템이 일반적인 3 채널 모노펄스시스템과 동등 이상의 추적성능을 가지면서 시스템의 구현측면에서 이점이 있음을 확인하였다. 또한, 이 연구로 향후 모노펄스 추적시스템 개발 시 제작비용 및 제품 소형화에 유리한 단일채널 모노펄스수신기 적용이 가능함을 확인하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제25권5호
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• pp.1115-1121
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• 2001

This paper presents the development of a tracking algorithm for shipborad satellite antenna systems which can enhance the tracking performance. In order to overcome some drawbacks of the conventional step tracking algorithm a new tracking algorithm is proposed. The proposed algorithm searches for the best tracking angles using gradient-based formulae and signal intensities measured according to a search pattern. The effectiveness of the proposed algorithm is demonstrated through simulation using real data.