• 한국전기전자재료학회논문지
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• 제21권6호
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• pp.530-537
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• 2008

This paper describes the results of a study on the tracking performance of outdoor insulating materials based on the rotating wheel dip test(RWDT). And, the influence of surface degradation was evaluated through such as measurement of the flashover voltage after and before tracking test, also aspects of surface degradation using scanning electron microscopy. The time to tracking breakdown of treated filled specimen is longer than untreated filled specimen. And, after the RWDT, the surface of specimen by adding untreated filler appeared heavy erosion. It was found that the addition to surface treated filler, the better tracking resistance. In the RWDT, the breakdown specimen is not affected by the dry flashover voltage, despite the fact that the surface degradation of tracking test has different state on each specimen. This suggests that wet flashover voltage play an important role in evaluating of tracking and erosion on the surface degradation in tracking test. And, the flashover voltage of specimen under wet conditions are greatly affected by the salt concentration and degree of degradation by the RWDT Because of hydrophobicity and degree of degradation by the RWDT, the flashover voltage of treated filled specimen is higher than that of untreated filled specimen. Different types of specimen may have different hydrophobicity and their surface state under contaminated conditions may not be the same.

• Journal of Electrical Engineering and Technology
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• 제10권2호
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• pp.688-698
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• 2015

This paper presents a modeling and a controller design for a hybrid wind turbine generator, especially with an operating mode of battery energy-storage system and a dumpload that contribute to the frequency control of the system while diesel-synchronous unit is not in operation. The proposed control scheme is based on a robust tracking controller, which takes an account of system uncertainties due to the wind flow and load variations. In order to provide robustness for system uncertainties, the range of operation is partitioned into three operating conditions as sub-models in the controller design. In the simulation study, the proposed robust tracking controller (RTC) is compared with the conventional proportional-integral (PI) controller. Simulation results show that the effectiveness of the RTC against disturbances caused by wind speed and load variation. Thus, better quality of the hybrid wind power system is achieved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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• pp.660-662
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• 2000

The most important problem in traget tracking can be said to be modeling the tracking system correctly. Although the simple linear dynamic equation for this model has used until now, the satisfactory performance could not be obtained owing to uncertainties of the real systems in the case of designing the filters based on the dynamic equations. In this paper, we propose the extended robust Kalman filter(ERKF) which can be applied to the real target tracking system with the parameter uncertainties. To solve the robust nonlinear fettering problem, we derive the extended robust Kalman filter equation using the Krein space approach and sum quadratic constraint. We show the proposed filter has better performance than the existing extended Kalman filter(EKF) via 3-dimensional target example.

• 전기학회논문지
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• 제63권11호
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• pp.1551-1558
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• 2014

We propose a multi-rate sensor fusion of vision and radar using Kalman filter to solve problems of asynchronized and multi-rate sampling periods in object vehicle tracking. A model based prediction of object vehicles is performed with a decentralized multi-rate Kalman filter for each sensor (vision and radar sensors.) To obtain the improvement in the performance of position prediction, different weighting is applied to each sensor's predicted object position from the multi-rate Kalman filter. The proposed method can provide estimated position of the object vehicles at every sampling time of ECU. The Mahalanobis distance is used to make correspondence among the measured and predicted objects. Through the experimental results, we validate that the post-processed fusion data give us improved tracking performance. The proposed method obtained two times improvement in the object tracking performance compared to single sensor method (camera or radar sensor) in the view point of roots mean square error.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권4호
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• pp.2075-2092
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• 2017

Person re-identification is to match pedestrians observed from non-overlapping camera views. It has important applications in video surveillance such as person retrieval, person tracking, and activity analysis. However, it is a very challenging problem due to illumination, pose and viewpoint variations between non-overlapping camera views. In this work, we propose a viewpoint invariant method for matching pedestrian images using orientation of pedestrian. First, the proposed method divides a pedestrian image into patches and assigns angle to a patch using the orientation of the pedestrian under the assumption that a person body has the cylindrical shape. The difference between angles are then used to compute the similarity between patches. We applied the proposed method to real-time global multi-object tracking across multiple disjoint cameras with non-overlapping field of views. Re-identification algorithm makes global trajectories by connecting local trajectories obtained by different local trackers. The effectiveness of the viewpoint invariant method for person re-identification was validated on the VIPeR dataset. In addition, we demonstrated the effectiveness of the proposed approach for the inter-camera multiple object tracking on the MCT dataset with ground truth data for local tracking.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권1호
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• pp.1-7
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• 2004

This paper describes the carbonization characteristics of a phenolic resin deteriorated by tracking under the environment of a fire. In the experiment, a liquids droplet of 1[％] NaCl was dripped on the phenolic resin to cause a tracking with 110[V], 220[V] voltages applied. It can be addressed from the experimental results that when an insulator is carbonized by an external fire, its structure is amorphous. If an insulator is carbonized by electrical cause, on the other hand, its structure would be crystalline. In order to observe the surface change of the phenolic resin, the tracking process was analyzed by using SEM. In the case that the materials are carbonized under heat or fire, the exothermic peak appears around 500[$^{\circ}C$]. This is one of the important factors to determine the cause of fires. As a result of DTA, the exothermic peaks of an untreated sample showed at 333.4[$^{\circ}C$], 495.7[$^{\circ}C$] but those of a sample deteriorated by tracking appeared at 430.6[$^{\circ}C$], 457.6[$^{\circ}C$] in a voltage of 110[V], and at 456.2[$^{\circ}C$], 619.7[$^{\circ}C$] in a voltage of 220[V]. It is possible, therefore, to distinguish a virgin sample from carbonized samples(graphite) by the exothermic peak.

• Journal of Electrical Engineering and Technology
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• 제13권1호
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• pp.460-467
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• 2018

Metaheuristic optimization approach has become the new framework for control synthesis. The main purposes of the control design are command (input) tracking and load (disturbance) regulating. This article proposes an optimal proportional-integral-derivative (PID) controller design for the DC motor speed control system with tracking and regulating constrained optimization by using the cuckoo search (CS), one of the most efficient population-based metaheuristic optimization techniques. The sum-squared error between the referent input and the controlled output is set as the objective function to be minimized. The rise time, the maximum overshoot, settling time and steady-state error are set as inequality constraints for tracking purpose, while the regulating time and the maximum overshoot of load regulation are set as inequality constraints for regulating purpose. Results obtained by the CS will be compared with those obtained by the conventional design method named Ziegler-Nichols (Z-N) tuning rules. From simulation results, it was found that the Z-N provides an impractical PID controller with very high gains, whereas the CS gives an optimal PID controller for DC motor speed control system satisfying the preset tracking and regulating constraints. In addition, the simulation results are confirmed by the experimental ones from the DC motor speed control system developed by analog technology.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.2094-2112
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• 2019

Focusing on the issue that the conventional Kernel Correlation Filter (KCF) algorithm has poor performance in handling scale change and obscured objects, this paper proposes an anti-occlusion and scale adaptive tracking algorithm in the basis of KCF. The average Peak-to Correlation Energy and the peak value of correlation filtering response are used as the confidence indexes to determine whether the target is obscured. In the case of non-occlusion, we modify the searching scheme of the KCF. Instead of searching for a target with a fixed sample size, we search for the target area with multiple scales and then resize it into the sample size to compare with the learnt model. The scale factor with the maximum filter response is the best target scaling and is updated as the optimal scale for the following tracking. Once occlusion is detected, the model updating and scale updating are stopped. Experiments have been conducted on the OTB benchmark video sequences for compassion with other state-of-the-art tracking methods. The results demonstrate the proposed method can effectively improve the tracking success rate and the accuracy in the cases of scale change and occlusion, and meanwhile ensure a real-time performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.2989-2991
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• 1999

We design the stable controller with variable gains and reference velocity in order to apply to this controller the proper gains and reference velocity generated with fuzzy logic in on-line. The proposed controller is applied to solve two problems including the reference velocity tracking problem and speedy tracking problem. The result of the simulation show a robust performance under the different conditions

• 한국화재소방학회논문지
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• 제33권2호
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• pp.30-38
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• 2019

전기 화재의 주요 원인 중 하나인 트래킹은 전기적 방전에 의한 물리적 현상으로 인식된다. 따라서 트래킹은 전계해석, 전자생성에 의한 도전성 경로, 기체방전이론을 기반으로 설명되어야 한다. 하지만, 이러한 사항을 반영한 연구논문은 드물다. 본 논문은 트래킹 진전에서 그들의 영향을 포함한 트래킹 진전 메커니즘을 제안하였다. 그 메커니즘의 제안을 위해, 트래킹 실험, 탄화진전 모델에 대한 전계해석, 연면방전 이론을 적용한 트래킹 진전과정에 대한 설명이 수행되었다. 트래킹 모의실험으로부터, 코로나 방전에서 트래킹 파괴까지 트래킹 진전의 각 단계에서 전류파형이 측정되었다. 전계해석은 탄화의 발생과 진전과정동안 건조대 표면의 전계와 전자생성을 위한 고전계 영역을 파악하기 위해 수행되었다. 본 논문에서 제안된 트래킹 메커니즘은 코로나 방전에 의한 전자사태, 양이온의 축적, 전자사태의 확장, 2차 전자사태, 스트리머, 도전성 경로에 의한 트래킹 파괴의 6단계로 구성된다. 트래킹 모의실험에서 측정된 펄스성 전류파형은 제안된 트래킹 메커니즘에 의해 설명될 수 있었다. 본 연구 결과는 화재의 원인인 트래킹을 검출하고, 내트래킹성을 높이는 데 필요한 기술 자료가 될 것이다.