• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -1
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• pp.501-504
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• 2000

In this paper, performance of a pseudonoise (PN) code tracking loop is analyzed and simulated for a direct-sequence/code-division multiple access ( DS/CDMA) system with imperfect power control in a multipath fading channel. A noncoherent first-order delay-locked loop (DLL) is considered as a PN code tracking loop. Power control error is modeled as a log-normally distributed random variable. From the simulation results, it is shown that for smaller discriminator offset, tracking jitter performance is improved while MTLL performance is degraded. It is shown that large power control error and heavy shadowing substantially degrade the PN tracking performance. The analysis in this paper can be applicable to design of PN code tracking loop for a DS/CDMA system.

• 반도체디스플레이기술학회지
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• 제18권1호
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• pp.53-58
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• 2019

Since floating facility with mooring system can be moved and rotated by wind or other environmental variables, the error in azimuthal angle must be compensated using a GPS receiver and geo-magnetic sensor. Accordingly, when an existing photovoltaic tracking algorithm is applied to a floating photovoltaic system, it is difficult to do the optimal solar tracking. In this paper, an effective azimuthal angle algorithm is develop for the photovoltaic tracking in floating condition. In order to verify the developed algorithm, the prototype of the floating photovoltaic system is manufactured and the developed algorithm is applied to the system. The algorithm shows a good tracking feasibility on the prototype.

• 전기학회논문지
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• 제66권4호
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• pp.682-691
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• 2017

In this paper, we propose the fusion design methodology of both pedestrian detection and object tracking system realized with the aid of HOG-PCA based RBFNN pattern classifier. The proposed system includes detection and tracking parts. In the detection part, HOG features are extracted from input images for pedestrian detection. Dimension reduction is also dealt with in order to improve detection performance as well as processing speed by using PCA which is known as a typical dimension reduction method. The reduced features can be used as the input of the FCM-based RBFNNs pattern classifier to carry out the pedestrian detection. FCM-based RBFNNs pattern classifier consists of condition, conclusion, and inference parts. FCM clustering algorithm is used as the activation function of hidden layer. In the conclusion part of network, polynomial functions such as constant, linear, quadratic and modified quadratic are regarded as connection weights and their coefficients of polynomial function are estimated by LSE-based learning. In the tracking part, object tracking algorithms such as mean shift(MS) and cam shift(CS) leads to trace one of the pedestrian candidates nominated in the detection part. Finally, INRIA person database is used in order to evaluate the performance of the pedestrian detection of the proposed system while MIT pedestrian video as well as indoor and outdoor videos obtained from IC&CI laboratory in Suwon University are exploited to evaluate the performance of tracking.

• 한국화재소방학회논문지
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• 제31권4호
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• pp.111-118
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• 2017

본 논문은 반단선과 트래킹에 의한 복합적 전기화재의 위험성분석에 관한 연구이다. 먼저, 단일원인인 반단선에 의한 전기화재 위험성을 분석하기 위해 전선의 소선 수 및 정격전류의 변화에 따른 열적특성을 측정하였다. 또한, 그 후 복합적 원인에 의한 전기화재 위험성을 분석하기 위해 반단선 상태에서 추가적으로 가속트래킹 실험을 실시하여 반단선과 트래킹의 화재연관성을 확인하였다. 실험결과 반단선이 단일원인으로 작용할 때의 전류에 의해 발생된 기존 열적특성과 트래킹이 복합적으로 작용함으로써 전류가 크게 증가되어 열적특성이 더욱 뚜렷이 나타나 단일원인에서 발생되지 않았던 급격한 온도상승으로 인한 소선의 단선이 복합적 원인에서 나타났다. 즉, 기존의 반단선에 의한 전기화재 위험성보다 반단선과 트래킹이 복합적으로 작용될 경우 상대적으로 그 위험성이 크게 증가되는 것을 확인할 수 있었다.

• 대한전자공학회논문지TC
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• 제39권4호
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• pp.216-224
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• 2002

본 논문은 이동하는 차량에서 DBS를 수신하기 위한 위성 추적 안테나 제어시스템의 성능을 기술하고 있다. 이 시스템의 안정도와 추적속도 개선을 위해, 방향센서의 기능이 종래의 좌우 추적 알고리즘에 추가되었다. DBS 수신을 위해 제작된 안테나 시스템의 위성 추적 실험이 고속도로와 도심지역에서 수행되었다. 고속도로에서 측정된 AGC 신호레벨은 TV 시청이 가능한 레벨 이상으로 관측되었다. 따라서 방향센서로 보상된 추적 알고리즘을 가진 하드웨어시스템의 우수한 성능이 확인되었다.

• 한국공작기계학회논문집
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• 제16권4호
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• pp.101-107
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• 2007

The objective of this research work is to investigate into effects of an auto tracking of the focal distance on the quality of the cut part in the cutting of a low carbon sheet using a high-power CW Nd:YAG laser. An auto-tracking system with a capacitance based distance control loop has been employed to perform a real control of the focal distance. In order to examine the influence of the auto-tracking of a focal distance on the optimum focal distance, the kerfwidth, surface roughness and the formation of the cut section, several linear cutting tests have been carried out using the auto-tracking system. The results of experiments have been shown that the optimum focal distance is 0.9mm. In addition, it has been shown that the variation of kerfwidth and the surface roughness of the cut part with control of the focal distance are reduced 40-80% and 30-55% in comparison with those of the cut part without tracking of the focal distance. From the results of the experiments, it has been found that the real time tracking of the focal distance can improve the part quality.

• 전기학회논문지
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• 제58권12호
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• pp.2520-2528
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• 2009

In this paper, we proposed tracking detection methodology using information granulation-based fuzzy radial basis function neural networks (IG-FRBFNN). According to IEC 60112, tracking device is manufactured and utilized for experiment. We consider 12 features that can be used to decide whether tracking phenomenon happened or not. These features are considered by signal processing methods such as filtering, Fast Fourier Transform(FFT) and Wavelet. Such some effective features are used as the inputs of the IG-FRBFNN, the tracking phenomenon is confirmed by using the IG-FRBFNN. The learning of the premise and the consequent part of rules in the IG-FRBFNN is carried out by Fuzzy C-Means (FCM) clustering algorithm and weighted least squares method (WLSE), respectively. Also, Hierarchical Fair Competition-based Parallel Genetic Algorithm (HFC-PGA) is exploited to optimize the IG-FRBFNN. Effective features to be selected and the number of fuzzy rules, the order of polynomial of fuzzy rules, the fuzzification coefficient used in FCM are optimized by the HFC-PGA. Tracking inference engine is implemented by using the LabVIEW and loaded into embedded system. We show the superb performance and feasibility of the tracking detection system through some experiments.

• Journal of Electrical Engineering and Technology
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• 제11권3호
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• pp.683-689
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• 2016

Most outdoor solid insulators may suffer from surface degradations due to non-stationary currents that flow on the insulator surface. These currents may be classified as leakage, discharge and tracking currents due to their disturbing potencies respectively. The magnitude of these currents depends on the degree of the contamination of surface. The leakage signals are followed by discharge signals and tracking signals which are capable of forming carbonized tracking paths on the surface between high voltage and earth contacts (surface tracking). Surface tracking is one of the most breakdown mechanisms observed on the solid insulators, especially polymers which may cause severely reduced lifetime. In this study the degradations observed on polyester resin based insulators are investigated according to the IEC 587 Inclined Plane Test Standard. The signals are monitored and recorded during tests until surface tracking initiated. In order to prevent total breakdown of an insulator, early detection of tracking signals is vital. Continuous Wavelet Transform (CWT) is proposed for classification of signals and their energy levels observed on the surface. The application of CWT for processing and classification of the surface signals which are prone to display high frequency oscillations can facilitate real time monitoring of the system for diagnosis.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.223-228
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• 2005

In oprical disk drives, surface defects on a disk distort tracking error signal and disturb a precision tracking control.. A conventional method against disk defect is held the tracking control signal when a defective portion is detected. However, if the defective portion is getting longer, objective lens will get away from following track. In order to keep the postion of spot from following track, the servo system must predict tracking error and control the object lens in the defective portion. A tracking control system for optical disk drives was proposed recently based on both Coprime Factorization(CF) and Zero Phase Erro. Tracking(ZPET) control. The system was proposed for overcome the limit of previously tracking error. But there were no research about the method against the defective portion. This paper proposes a new and simple ZPET construct. as a new method against the defective portion. From experimental results, we have proved that proposed method improves the performance against the defective portion, decreases the uncertainty of a model, and requires less memory than the previously proposed method.

• 항공우주기술
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• 제10권1호
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• pp.116-121
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• 2011

나로우주센터 추적레이더가 획득한 실시간 위치 정보는 발사통제시스템에서 위치, 속도, 비행궤도 표시, 예상궤도 진입여부 및 안전을 위한 비행종료시점 판단 등의 중요한 데이터로 사용된다. 추적레이더에서 발사통제시스템으로 전송하는 표적의 위치 정보는 추적레이더 중심의 좌표값 데이터이며, 발사통제시스템에서 추적레이더로 전송하는 Slaving 데이터는 발사대 중심의 좌표값 데이터이다. 이렇듯 추적레이더와 발사통제시스템 간의 송수신 데이터는 각 시스템에 맞게 적절하게 좌표 변환이 수행되어야 한다. 본 연구에서는 나로우주센터 추적레이더 간의 상호 데이터 송수신 및 발사통제시스템과의 데이터 통신에 사용되는 각각의 좌표계 및 좌표계 간의 좌표 변환에 대해 기술하였다.