• Title/Summary/Keyword: tracker

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DEVELOPMENT OF PRECISION ATTITUDE DETERMINATION SYSTEM FOR KOMPSAT-2

  • Yoon Jae-Cheol;Shin Dongseok;Lee Hungu;Lee Young-Ran;Lee Hyunjae;Bang Hyo-Choong;Cheon Yee-Jin;Shin Jae-Min;Moon Hong-Youl;Lee Sang-Ryool;Jeun Gab-Ho
    • Bulletin of the Korean Space Science Society
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    • 2004.10b
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    • pp.296-299
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    • 2004
  • KARI precision attitude determination system has been developed for high accurate geo-coding of KOMPSAT-2 image. Sensor data from two star trackers and a IRU are used as measurement and dynamic data. Sensor data from star tracker are composed of QUEST and unit vector filter. Filter algorithms consists of extended Kalman filter, unscented Kalman filter, and least square batch filter. The type of sensor data and filter algorithm can be chosen by user options. Estimated parameters are Euler angle from 12000 frame to optical bench frame, gyro drift rate bias, gyro scale factor, misalignment angle of star tracker coordinate frame with respect to optical bench frame, and misalignment angle of gyro coordinate frame with respect to optical bench frame. In particular, ground control point data can be applied for estimating misalignment angle of star tracker coordinate frame. Through the simulation, KPADS is able to satisfy the KOMPSAT-2 mission requirement in which geo-location accuracy of image is 80 m (CE90) without ground control point.

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The Reliability and Validity Testing of Korean Version of the Pittsburgh Sleep Quality Index (한국어판 피츠버그 수면의 질 지수(PSQI-K) 도구의 신뢰도와 타당도 검증)

  • Shin, Seunghwa;Kim, Su Hyun
    • Journal of Convergence for Information Technology
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    • v.10 no.11
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    • pp.148-155
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    • 2020
  • The purpose of the study was to test the reliability and validity of the Korean version of Pittsburgh Sleep Quality Index (PSQI-K) and to examine the cutoff point of the PSQI-K for screening insomnia among young adults. The subjective quality and patterns of sleep in 64 participants were measured using PSQI-K and Fitbit Charge 3TM. The properties of the instrument were analyzed using Cronbach's alpha coefficient for the internal consistency reliability, factor analysis for the construct validity, and Spearman's rho correlation coefficient for the correlation between the PSQI-K total scores and Fitbit tracker scores. The Cronbach's alpha coefficient of the PSQI-K was 0.69. The Spearman's rho correlation coefficient between the PSQI-K and Fitbit tracker was higher than 0.67. A cutoff point of ≥6.0 had a sensitivity of 0.93 and a specificity of 0.84. In conclusion, the PSQI-K is a reliable and valid instrument to evaluate sleep disturbance in Korean young adults.

Longitudinal Control Using Linear Quadratic Tracker with Integrator and Handling Qualities for Unmanned Rotorcraft (LQTI를 이용한 회전익 무인항공기 종방향 조종성 평가를 위한 제어법칙 설계 및 조종성 평가)

  • Lee, Changmin;Kim, Sungkeun;Jo, Seunghwan;Ra, Chunggil;Kim, Ki-joon;Suk, Jinyoung;Kim, Seungkeun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.45 no.5
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    • pp.393-400
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    • 2017
  • A virtual simulation test program to carry out the handling qualities of unmanned Rotorcraft has developed by using the MATLAB GUIDE(Graphic User Interface Development Environment). The handling quality evaluation program based on ADS-33E contributes to design the flight control system and to evaluate handling qualities. In addition, Linear Quadratic Tracker with Integrator(LQTI) attitude controller based on Linear Quadratic Regulator(LQR) for to rotorcraft BO-105C and the effects of the handling qualities is analyzed change to weight matrices of the Q and R.

Power Save of Marine Tracker Buoy System Based on NB-IoT for Identification of Fishing Gear (어구 자동 식별을 위한 NB-IoT 기반의 해양 트래커 부이 시스템의 전력 절감)

  • Nam, Sung-Il;Kim, Min-Hoon
    • Journal of Advanced Navigation Technology
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    • v.22 no.6
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    • pp.545-550
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    • 2018
  • Ministry of Oceans and Fisheries declared action plan for the electric fishing gear using real name in order to prevent overusing the fishing gear and to reduce discarded fishing gear. It is needed for a technique that can efficiently transmit the information including the type and location of the fishing gear and the user's real name to the fishing boat and the control center using IoT-based communication. The marine tracker buoy system, which is placed on the water for a long time, transmit the position data and the state data of the buoys to the control center in the ground by using NB-IoT channels. In this paper, we propose the algorithm for the low-power operation of the marine tracker buoy system is proposed and test results of current consumption in the marine tracker buoy system with the proposed algorithm is investigated.

Quasi-Optimal DOA Estimation Scheme for Gimbaled Ultrasonic Moving Source Tracker (김발형 초음파 이동음원 추적센서 개발을 위한 의사최적 도래각 추정기법)

  • Han, Seul-Ki;Lee, Hye-Kyung;Ra, Won-Sang;Park, Jin-Bae;Lim, Jae-Il
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.2
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    • pp.276-283
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    • 2012
  • In this paper, a practical quasi-optimal DOA(direction of arrival) estimator is proposed in order to develop a one-axis gimbaled ultrasonic source tracker for mobile robot applications. With help of the gimbal structure, the ultrasonic moving source tracking problem can be simply reduced to the DOA estimation. The DOA estimation is known as one of the representative long-pending nonlinear filtering problems, but the conventional nonlinear filters might be restrictive in many actual situations because it cannot guarantee the reliable performance due to the use of nonlinear signal model. This motivates us to reformulate the DOA estimation problem in the linear robust state estimation setting. Based on the assumption that the received ultrasonic signals are noisy sinusoids satisfying linear prediction property, a linear uncertain measurement model is newly derived. To avoid the DOA estimation performance degradation caused by the stochastic parameter uncertainty contained in the linear measurement model, the recently developed NCRKF (non-conservative robust Kalman filter) scheme [1] is utilized. The proposed linear DOA estimator provides excellent DOA estimation performance and it is suitable for real-time implementation for its linear recursive filter structure. The effectiveness of the suggested DOA estimation scheme is demonstrated through simulations and experiments.

Development of a Highly Efficient Isolation Protocol for Mitochondrial DNA and RNA Using Small Scale Plant Tissues (식물의 초경량 조직을 이용한 미토콘드리아의 DNA와 RNA 정제)

  • Kim Kyung-Min;Lim Yong-Suk;Shin Dong-Ill;Sul Ill-Whan
    • Journal of Life Science
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    • v.16 no.2 s.75
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    • pp.240-244
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    • 2006
  • We present a fast and simple protocol for purification of mitochondria, mitochondrial DNA, and RNA from small amounts of tomato leaves. This method uses a high ionic strength medium to isolate mitochondria and extract mitochondrial DNA and RNA from a single preparation and is easily adaptable to other plant species. Mitochondria was confirmed by MitoTracker. The mitochondrial DNA was not contaminated by plastid DNA, was successfully used for PCR. Similarly, the isolated mitochondrial RNA was not contaminated only slightly contaminated (leaves) by plastid RNA. RNA prepared according to our method was acceptable for RT-PCR analysis

Development of a Robot Performance Evaluation System Using Leica LTD 500 Laser Tracker (레이저 트랙커(Leica LTD 500)를 이용한 로봇 성능 평가 시스템 개발)

  • Kim Mi-Kyung;Yoon Cheon-Seok;Kang Hee-Jun;Seo Yeong-Su;Ro Young-Shick;Son Hong-Rae
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1001-1006
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    • 2005
  • A Robot Performance Evaluation System(RPES) with the laser tracker Leica LTD 500 was developed according to the ISO 9283 robot performance criteria. The developed system is set up a test robot to continuously move the prescribed cyclic trajectories without a human intervention and the laser tracker to simultaneously measure the robot's movement. And then, the system automatically extracts the required data from the tremendous measured data, and computes the various performance criteria which represents the present state of the test robot's performance. This paper explains how ISO 9283 robot performance criteria was used for the developed system, and suggests a automatic data extraction algorithm from the mass of measured data. And also, a user-friendly Robot Performance Evaluation System(RPES) Software was developed with Visual Basic satisfying the need of Hyundai Motor Company. The developed system was implemented on NACHI 8608 AM 11 robot. The resulted output shows the effectiveness of the developed system.

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Digital Fine Timing Tracker for Correlation Detection Receiver in IR-UWB Communication System (IR-UWB 시스템에서 상관 검출 수신기를 위한 디지털 미세 타이밍 추적기)

  • Ko Seok-Jun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.9C
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    • pp.905-913
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    • 2006
  • In the impulse radio ultra-wideband communication systems, the residual timing offset exists when the acquisition and tracking of the timing synchronization is well done. And the offset affects the performance of the system dramatically. In order to compensate the offset, we present the digital phase-locked loop that uses the reference signal in the correlation detection receiver. First, we show the degradation of BER performance that is caused by the offset, and then compensation process of the timing tracker and performance improvement. In this paper, the timing detector in the tracker operates at the sampling period of frame level uses the correlation between received and reference signal. Also, we present the performance comparison by using the computer simulation results for different Gaussian monocycle pulses.

Adaptive MCMC-Based Particle Filter for Real-Time Multi-Face Tracking on Mobile Platforms

  • Na, In Seop;Le, Ha;Kim, Soo Hyung
    • International Journal of Contents
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    • v.10 no.3
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    • pp.17-25
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    • 2014
  • In this paper, we describe an adaptive Markov chain Monte Carlo-based particle filter that effectively addresses real-time multi-face tracking on mobile platforms. Because traditional approaches based on a particle filter require an enormous number of particles, the processing time is high. This is a serious issue, especially on low performance devices such as mobile phones. To resolve this problem, we developed a tracker that includes a more sophisticated likelihood model to reduce the number of particles and maintain the identity of the tracked faces. In our proposed tracker, the number of particles is adjusted during the sampling process using an adaptive sampling scheme. The adaptive sampling scheme is designed based on the average acceptance ratio of sampled particles of each face. Moreover, a likelihood model based on color information is combined with corner features to improve the accuracy of the sample measurement. The proposed tracker applied on various videos confirmed a significant decrease in processing time compared to traditional approaches.

A Study on The Gamification Elements of Eye-tracker for Improving Attention Concentration of Children with Quadratic Palsy with Intellectual Disability (지적장애를 동반한 사지마비형 뇌성마비 아동의 주의집중력 향상을 위한 아이트래커기반 게임화 요소 연구)

  • Jeong, Yoona;Woo, Tack
    • Journal of Korea Game Society
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    • v.20 no.4
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    • pp.57-66
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    • 2020
  • In this paper, we analyze the interaction features using eye-tracker and the characteristics of attention concentration of children with intellectual disabilities, and present gamification elements that can be used when designing digital contents for them. For children with quadriplegic cerebral palsy, eye-trackers will increase the accessibility of digital contents. Foreground gamification can be used for selective attention concentration, background gamification and intrinsic motivation to sustain attention concentration, and foreground gamification and extrinsic motivation for mobility.