• Proceedings of the Korean Information Science Society Conference
• /
• 2004.04b
• /
• pp.502-504
• /
• 2004

지능형 교통 정보 시스템을 구축할 때 반드시 요구되는 것이 바로 위치 정보이다. 대부분 GPS (Global Positioning System)와 같은 장치를 이용하여 위치 정보를 얻게 된다. 그러나 GPS수신기와 같은 장치는 상대적으로 비용이 크기 때문에 차량마다 장착하여 지능형 교통 정보 시스템에 활용하기에는 부담이 된다. 따라서 본 논문에서는 기존의 무선랜으로 위치를 추적하는 방법을 버스 지능형 교통 정보 시스템에 적용한 시스템 구조를 제안한다. 버스는 노선의 자유도가 택시 같은 다른 교통편에 비해서 작으므로 무선랜으로 위치 추적하는 방법은 다른 위치 추적 방법에 비해 경제적으로 보다 적합하다.

• Journal of Institute of Control, Robotics and Systems
• /
• v.14 no.1
• /
• pp.7-12
• /
• 2008

A GNSS(Global Navigation Satellite System) using GPS provides us with very useful information concerning the positioning of users in many sectors such as transportation, social services, the justice system and customs services, public works, search and rescue systems and leisure. A GNSS using the Galileo satellite is due to work in 2008 and expected to be used in various fields such as aviation, marine transportation, land surveying, resources development precise agriculture, telemetics, and so on. In this paper, we discuss the implementation and testing of a combined GPS/Galileo receiver which we named KSTAR V1.0. Each tracking module of GPS/Galileo dual mode correlator has the five track arms which consist of Very Early code, Early code, Prompt code, late code, and Very late code. Each of 24 tracking modules can be assigned to GPS and/or Galileo signal by changing mode selection register. The basic correlator integration dump period is set to 1ms for GPS C/A code and fast Galileo signal tracking. The performance of the developed combined GPS/Galileo receiver was tested and evaluated using the IF (Intermediated Frequency)-level GPS/Galileo signal generator.

• Journal of Positioning, Navigation, and Timing
• /
• v.1 no.1
• /
• pp.1-6
• /
• 2012

For a Global Positioning System (GPS) receiver, it is known that a Vector Delay Locked Loop (DLL) in which the code signals of each satellite are tracked in parallel by using navigation results shows better performance in the aspect of the tracking accuracy and the robustness than that of a Scalar DLL. However, the quantitative analysis and the logical grounds for that performance enhancement of the Vector DLL are not sufficient. This paper, therefore, proposes the structure of the GPS receiver with the Vector DLL and analyzes the performance of it. The tracking and the positioning accuracy of the Vector DLL are theoretically analyzed and confirmed by simulation results. From the simulation results, it can be seen that the tracking and positioning accuracy has been improved about 30% in case that the receiver is static and the positioning is conducted for every Pre-detection Integration Time (PIT) while C/N0 is 45 dB-Hz.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.7
• /
• pp.559-565
• /
• 2014

In this paper, we propose an unambiguous correlation function for time-multiplexed binary offset carrier (TMBOC) signal tracking. Specifically, considering that the TMBOC modulation transmits two kinds of sine-phased BOC signals in time domain alternatively, we generate sub-correlation functions for each of the BOC signals by using split sine-phased BOC signals, and then, obtain a correlation function with no side-peak by recombining the sub-correlation functions. From numerical results, we confirm that the proposed correlation function offers an improved tracking error standard deviation performance than the TMBOC autocorrelation function.

• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.5
• /
• pp.467-473
• /
• 2007

In this paper, we present a position-based robot hand tracking scheme where a pan-tilt camera is controlled such that a robot hand is always shown in the center of an image frame. We calculate the rotation angles of a pan-tilt camera by transforming the coordinate systems. In order to identify the model parameters, we applied two optimization techniques: a nonlinear least square optimizer and a particle swarm optimizer. From the simulation results, it is shown that the considered parameter identification problem is characterized by a highly multimodal landscape; thus, a global optimization technique such as a particle swarm optimization could be a promising tool to identify the model parameters of a robot hand tracking system, whereas the nonlinear least square optimizer often failed to find an optimal solution even when the initial candidate solutions were selected close to the true optimum.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.26 no.9
• /
• pp.828-836
• /
• 2015

In this paper, the assessment technique for track accuracy in the phased array radar is proposed. It is assumed that ${\alpha}-{\beta}$ tracking filter to track the target is established in the phased array radar. In order to assess the track accuracy strictly, we should use the real target position data acquired from the special instrument, ACMI(Air Combat Maneuvering Instrument) pod or DGPS(Differential Global Positioning System). However, this method leads to increase the experiment cost and test time. We derive the relationship between the residuals of tracking filter and the standard deviations of range and angle tracking errors which are assigned as track assessment index. The theory of sample variance is introduced in this assessment because track accuracy has to be calculated with many residual samples.

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.10
• /
• pp.869-875
• /
• 2016

In this paper, a novel scheme with which to mitigate a repeat-back jamming effect is proposed for the GPS L1 coarse/acquisition signal. The proposed scheme estimates the code tracking bias caused by repeat-back jamming signals using a Combined Pseudo-random noise signal. It then mitigates the repeat-back jamming effect by subtracting the estimated code timing on a normal correlation channel from the estimated value. Through a Monte-Carlo simulation, the proposed scheme can diminish the running average of code tracking bias to less than 10% of the bias using the conventional scheme.

• Aerospace Engineering and Technology
• /
• v.12 no.1
• /
• pp.64-72
• /
• 2013

This paper describes the analysis of the tracking and navigation performance of a GPS receiver in a launch vehicle simulation when the carrier tracking loop is designed as a 3rd order phase-locked loop with variable bandwidths. There are differences of tracking and navigation performance according to the variable bandwidths under the dynamics condition. When the bandwidth is set to narrow, the GPS receiver could not track the satellite signals so that the navigation information could not be calculated.

• Journal of Power Electronics
• /
• v.19 no.5
• /
• pp.1248-1258
• /
• 2019

This paper presents a moth-flame optimization (MFO)-based maximum power point tracking (MPPT) method for photovoltaic (PV) systems. The MFO algorithm is a new optimization method that exhibits satisfactory performance in terms of exploration, exploitation, local optima avoidance, and convergence. Therefore, the MFO algorithm is quite suitable for solving multiple peaks of PV systems under partial shading conditions (PSCs). The proposed MFO-MPPT is compared with four MPPT algorithms, namely the perturb and observe (P&O)-MPPT, incremental conductance (INC)-MPPT, particle swarm optimization (PSO)-MPPT and whale optimization algorithm (WOA)-MPPT. Simulation and experiment results demonstrate that the proposed algorithm can extract the global maximum power point (MPP) with greater tracking speed and accuracy under various conditions.

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.06c
• /
• pp.417-421
• /
• 2007

본 논문에서는 악보 영상을 인식하고 이를 연주할 수 있는 시스템을 제안한다. 이 시스템은 스캐너 또는 카메라로 악보 영상을 입력 받는다. 먼저 입력 영상을 전처리하여 영상 분석에 알맞은 형태로 변환시키고 선 추적으로 오선을 추출한 후, 템플릿 매칭을 이용해 음표, 쉼표, 보표, 조표 등을 추출하여 인식한다. 그리고 인식한 결과를 MIDI로 출력한다. 이 악보 인식 시스템을 통해 여러 실험 데이터를 검토해 본 바, 본 시스템이 실용적임을 보였다.