• The Journal of the Institute of Internet, Broadcasting and Communication
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• 제16권2호
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• pp.93-99
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• 2016

In this paper, higher order coupler using small size waveguide which applicable for mobile Ku-band multimode monopulse satellite tracking antenna system, has been designed, implemented and tested. Proposed higher order mode coupler adopts a coaxial structure for low profile characteristic considering installation property to mobile satellite terminal system. In addition, by using proposed coupler, extracted tracking error signal pattern has measured and confirmed that required tracking accuracy is satisfied in desired frequency band. In the future, proposed coupler could utilize for multimode monopulse satellite tracking system for high tracking accuracy.

• Journal of Institute of Control, Robotics and Systems
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• 제12권8호
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• pp.739-745
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• 2006

This paper presents performance improvement of the INS velocity-adided GPS carier tracking loop. To this end, INS velocity-aided GPS carrier tracking loop was modeled as a feedfoward and a feedback loop system. In the phase tracking loop, it was shown that the tracking error caused by the dynamic motion of the vehicle can be compensated with the aiding of the INS information irrespective of the loop order and bandwidth. However, the signal trcking error increases as the INS error increases. It was also shown that in order to remove the tracking error caused by INS bias error, more than or equal to 2nd order PLL should be used. Experiments were carried out and the experimental results were compared with the analysis results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1049-1053
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• 2007

Cogged belts get unpleasant noise when the speed is up and down. This paper investigates optimum condition for reducing a belt noise that is caused by a belt shape and properties of the material. Order tracking is used analyze belt noise. First step, the pitch length exerts an important influence on the order noise. Second step, material of belt is also important for reducing noise level. The experimental results showed the modified form and material of belts to reduce the noise.

• Journal of the Korean Professional Engineers Association
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• 제42권6호
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• pp.53-57
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• 2009

Antenna Tracking System has been required core technology with special tracking algorithm, and it can be achieved by program tracking, step tracking, optracking, and monopulse tracking as well. Depend on tracking requirement we might be able to apply eligible tracking method in accordance with Geostationary and Inclined Orbit Satellite. Further, we should deeply consider two important factors in order to act up to customer expectation in quality and system performance including competitive price therefore we need maximized endeavor to upgrade not only tracking system performance, but reduction of product through engineering skill and R&D investment.

• Proceedings of the KIEE Conference
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.781-783
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• 1995

This paper presents a algorithm of hierarchical approach to tracking problems for high order systems via BPF. In controlling the n-th oder systems for tracking problem, TPBVP has the 2n-th order. Generally, it is very difficult to otain the solutions due to its high order. In order to solve this fact, hierarchical approach is applied. And using the BPF Transformation, we simply obtained the solutions of decomposed low order TPBVP from the recursive algebraic equations.

• Journal of the Korea Institute of Military Science and Technology
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• 제8권3호
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• pp.24-32
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• 2005

This paper describes the tracking filter performance for Naval Gun Ballistic Computation Unit(BCU). BCU needs tracing filter for gun firing. Using data of tracking sensor, BCU calculates the future position of Target and Gun order in the time of flight. In this paper, tracing filter is designed with interacting multiple model(IMM). The tracking algorithm based on the IMM requirers a considerable number of sub-model for the various maneuvering target in order to have a good performance. But, in the case of ship target, the maneuvering is restricted compared with the air target. Considering the maneuvering properties and adjusting the mode transition probabilities and the process noise of sub-model, We designed the IMM3 algorithm for Naval tracking filter with three sub-model.

• Journal of KSNVE
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• 제2권2호
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• pp.117-123
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• 1992

In the study, the design method of reconstruction filter is studied for synchronized sampling which is necessary for order tracking in rotating machinery. The original data sampled at constant intervals, using fixed anti- aliasing filters, is reconstructed by digital reconstruction filter and is resampled at new sampling times calculated by a suitable shaft angle encoder pulse arrival times in order to synchronize with shaft velocity. In addition to eliminating the tracking synthesizer and filters, this new method has no phase noise due to phase-locked loops.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제39C권4호
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• pp.380-386
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• 2014

In this paper, a higher-order mode coupler using coaxial-structure waveguide for Ku-band monopulse satellite tracking is proposed. The proposed higher-order mode coupler is built in a coaxial structure for compactness and weight reduction, making it suitable for mobile tracking systems. The inner circular waveguide of coaxial-structure is used to extract the fundamental mode signal and the high-order mode signal is extracted from the four slots of the outer circular waveguide and then transmitted via given stepped rectangular waveguide structure. The simulated results show that proposed higher-order mode coupler covers 250 MHz(12.75 GHz ~ 13.00 GHz) bandwidth with return loss and insertion loss characteristics. The antenna patterns of fundamental mode and higher-order mode applicable to monopulse tracking are generated successfully. Designed higher-order mode coupler using coaxial waveguide structure for Ku-band is expected to be used for high precision monopulse satellite tracking systems.

• 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.

• International Journal of Advanced Culture Technology
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• 제7권4호
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• pp.302-307
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• 2019

In this paper, we propose an efficient method for AR toolkit Vuforia. In order to increase the scan rate when using the 3D object scanner, the scan rate parameters need to be analyzed in terms of the angle and distance. In addition, in order to increase the tracking rate when tracking an object, the tracking rate has to be evaluated according to the position, complexity, and contrast of the object. To this end, we have defined the difference of scan rate according to angle and distance between camera and object when using object scanner and the recognition time according to object's position, complexity and contrast when tracking object.