• KIEAE Journal
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• v.11 no.2
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• pp.3-8
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• 2011

This study was carried out for analysing the relationship of environmental factors and the reduction rate of land compensation of six urban development projects near waste landfill sites located in the Seoul metropolitan area. For a close investigation, 24 variables were selected but only 4 environmental variables were identified to have high correlation to the reduction rate of compensation. These are fine particles(PM10), bad smell, the ratio of a greening zone of land and park, and the distance in straight line from the landfill site. Two variables-PM10 and bad smell-were found to have an effect on the average reduction rate of land compensation by correlation analysis. On the other hand, the ratio of a greening zone and the distance in straight line from the landfill site have been rejected for the significance test. The result of regression analysis of six models for the search of affecting variables on the reduction rate of compensation is that PM10 and bad smell have the impact ratio of more than 0.5. But the ratio of greening zone and the distance from the landfill are not significant factors, having the impact ratio of 0.025~0.045 except one model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.914-919
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• 2010

It is confirmed that as the distance measurements accuracy of the SDS-TWR(Symmetric Double-Sided Two-Way Ranging) based on CSS(Chirp Spread Spectrum) is considerably degraded due to frequency interference and it causes to severe errors in the localization applications. In this paper, the compensation algorithm based on error rate offset of distance measurement ($CA_d$) is proposed for the purpose to reduce the ranging errors due to by the SDS-TWR ranging problems. The $CA_d$ measures the distance values between two nodes by means of 1m interval about 1~25m distances in the SDS-TWR, and compensates the distance values using the parameters related to the distance compensation. From the experiments, it is analyzed that the $CA_d$. have reduced the distance error to average 95cm and maximum 526cm, and the distance error by the $CA_d$ was below about 60cm in the 25m distances. In particular, the performance of the distance measurements accuracy by the $CA_d$ is very high in LOS(Line Of Sight) environments.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.3 s.22
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• pp.56-63
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• 2005

The radome boresight error degrades the microwave seeker ability and the missile guidance performance. It increases the miss distance, also. This paper propose a method of radome boresight error measurement and compensation. The compensation method consist of radome analysis and radome compensation. In the radome analysis stage, we can know that the electromagnetic characteristics distorted by radome. In the compensation stage, the look-up table is built and used for compensation. The test uses a FMS(Flight motion simulator) and adjusts the FMS setup error for more accuracy. The result shows that not using an elaborate radome measurement equipment, the radome boresight error is well compensated easily.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.418-420
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• 2005

This paper proposed ultrasonic distance measurement module development for correct distance detection with collision escaping or obstacle of mobile robot is traveling self-regulation. Representative ultrasonic module applied in existing was Polaroid company's 6500 series and Devantech company's SRF04/SRF08 series. This ultrasonic sensors are corrupted by systematic errors due mainly to the dependency of sound speed upon surrounding conditions and random errors of uncertain origin. Therefore Ultrasonic distance detecting means of error compensation method and high definition, narrow beam angle, board area distance detecting means to apply to ultrasonic mobile robot control urgently need. In this paper use internal type temperature compensation method to improve problem of ultrasonic distance measurement method instead of that volume that have shortcoming of used correct temperature compensation methods applied big addition device. Compensate error by environment change of temperature. Humidity density etc. and is applicable to mobile robot offering various interface and real-time processing developed possible distance measurement module.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3571-3577
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• 2010

The estimated location coordinator exploration scheme and the E&E(Equivalent distance rate & Estimated location coordinator exploration) compensation algorithm for localization is proposed, and the performance of the E&E is analyzed in this paper. The proposed scheme is adapted to the AEDR(Algorithm for localization using the concept of Equivalent Distance Rate). From several experiments, it is confirmed that the performance of the localization compensation in SDS-TWR is improved from 0.60m to 0.34m in four experimental scenarios, and the performance of the localization compensation ratio of the E&E is also better than that of the AEDR as a level of maximum 15%. It can be thought that the proposed localization compensation algorithm E&E can be sufficiently applicable to various localization applications because the performance of the localization error rate of the E&E is measured as less than 1m in 99% of the total performance experiments.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.9
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• pp.947-953
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• 2011

Radome aberration error causes degradation of miss distance as well as stability of high maneuver missile system with RF seeker. A study about radome compensation method is important in this kind of missile system design. Several kinds of methods showed good compensation performance in their paper. Proposed adaptive Particle filter estimates line of sight rate excluding the radome induced error. This paper shows effectiveness of adaptive Particle filter as compensation method of radome aberration error. Robust performance of this filter depends on external aiding measurement, target acceleration. Tuning of system error covariance can make this filter unsensitive against the error of target acceleration information. This paper demonstrates practical usage of adaptive Particle filter for reducing miss distance and increasing stability against disturbance of radome aberration error through performance analysis.

• Journal of Electrical Engineering and Technology
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• v.7 no.4
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• pp.524-529
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• 2012

This paper proposes a novel control strategy of a PV tracking system considering the shadow influence. If distance of between PV arrays is not enough, shadow can be occurred to PV module. In PV system, if shadow is occurred to PV modules then PV modules operates reverses bias, and will eventually cause hot-spot and loss. To reduce loss by shadow influence, this paper proposes shadow compensation algorithm using distance between arrays and shadow length of array. The distance between arrays is calculated by using azimuth of solar, and length of array shadow is calculated using by altitude of solar. The shadow compensation algorithm proposed in this paper compares distance between arrays and length of array shadow. When the shadow length is longer than the distance between arrays, the algorithm adjusts altitude of array to avoid the shadow effects. The control algorithm proposed in this paper proves validity through compared with conventional algorithm and proposes experiment result.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.10
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• pp.593-601
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• 2003

Distance realy is tripped by the line impedance calculated at the relay point. Accordingly the accurate operation depends on the precise calculation of line impedance. Impedance can be accurately calculated in case of overhead line. However, in case of power cables or combined transmission lines, impedance can not be accurately calculated because cable systems have the sheath, grounding resistance, and sheath voltage limiters(SVLs). There are also several grounding systems in cable systems. Therefore, if there is a fault in cable systems, these terms will severely be caused much error to calculation of impedance. Accordingly the proper compensation should be developed for the correct operation of the distance relay. This paper presents the distance calculating algorithm in combined transmission line with power cable using wavelet transform. In order to achieve such purpose, judgement method to discriminate the fault section in both sections was proposed using D1 coefficient summation in db4. And also, error compensation value was proposed for correct calculation of impedance in power cables section.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5B
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• pp.370-376
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• 2012

The CSS(Chirp Spread Spectrum) technology is used for developing various WPAN(Wireless Personal Area Network) application fields in general, and it can be adapted to implement localization systems especially using SDS-TWR(Symmetric Double Sided - Two Way Ranging). But the ranging errors are occurred in many practical applications due to some interferences by some experiments. Thus, the compensation algorithm for localization is required for developing localization applications. The suggested compensation algorithm that is named KF_EDR(Kalman Filter and Equivalent Distance Rate) for localization in order to reduce the ranging errors is suggested in this paper. The KF_EDR compensation algorithm for localization is mainly composed of the AEDR(Algorithm of Equivalent Distance Rate) and the Kalman Filter. It is confirmed that the improved error ratio of the KF_EDR are 10.5% and 4.2% compared with the AEDR algorithm in lobby and stadium. From the results, it is analyzed that the KF_EDR can be widely used for some localization system in ubiquitous society.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.4
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• pp.740-749
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• 2015

In the visible light (VL) communication based on the conventional LED lights, depending on the increase of the communication range, the signal received at the photodiode of the VL receiver has usually the random distorted and decreased amplitude due to the path loss and fading effects of the VL channel. In order to overcome this problem, we propose, design, and implement the visible light communication circuit based on the comparator threshold voltage, where has a built-in distance compensation function. In addition, the performance of the proposed technique is evaluated and analyzed depending on the distance and communication speed through comparing the proposed VLC system based on the threshold voltage with the conventional one.