• Title/Summary/Keyword: Way Point

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A Way-Point Tracking of Hovering AUV by PID control (PID 제어기를 이용한 호버링 AUV의 경유점 추적)

  • Kim, Min J.;Bae, Seol B.;Baek, Woon-Kyung;Joo, Moon G.;Ha, Kyoung Nam
    • IEMEK Journal of Embedded Systems and Applications
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    • v.10 no.4
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    • pp.257-264
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    • 2015
  • For the tracking of the way-points of hovering AUV (HAUV), we suggest a simple PID controller. The way-points are designed to approach to a virtual underwater structure and the heading angles at each way-point are set to look at the structure in the face. The proposed controller consists of a vertical controller to maintain the depth and pitch angle, and a horizontal controller to move to the desired position as well as to adjust the heading angle of the HAUV. In the simulation using Matlab/Simulink, the HAUV with the proposed PID controller is shown to track all the way-points within 1 m range while maintaining proper heading angle at each way-point.

A Study on Way-Point Tracking of AUV using State Feedback (상태 궤환을 사용한 AUV의 경우점 추적 연구)

  • Kwon, Soon-Tae;Baek, Woon-Kyung;Kang, In-Pil;Choi, Hyeung-Sik;Joo, Moon-G.
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.12
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    • pp.1266-1272
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    • 2011
  • For way-point tracking of an autonomous underwater vehicle, a state feedback controller was designed by using pole placement scheme in discrete time domain. In the controller, 4 state variables were used for regulating the depth of the vehicle in z direction, and 3 state variables, for steering the vehicle in xy plane. Assuming constant speed of AUV, we simplified the design of the way-point tracking system. The proposed controller was simulated by MATLAB/Simulink using 6 degree-of-freedom nonlinear model and its performance of way point tracking was shown to be fulfilled within 1 m, nevertheless the proposed controller is quite simple and easy to implement compared to sliding mode controller.

Two-Way Relaying-Based Two-Hop Two-User Multiple-Input Multiple-Output System

  • Cho, Young Seek;Choi, Seyeong
    • Journal of information and communication convergence engineering
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    • v.12 no.2
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    • pp.67-74
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    • 2014
  • In multi-hop communication systems, two-way relaying is one of the solutions to mitigate the spectral efficiency loss caused by a half-duplex transmission. In this paper, a simple two-way relaying scheme is proposed for two-hop two-user multiple input multiple output (MIMO) systems. In the proposed system, a base station and a relay station (RS), both equipped with two antennas, form a point-to-point MIMO channel, while the RS and two single-antenna mobile users form a point-to-multipoint multiuser (MU)-MIMO channel. Numerical examples show that the proposed system achieves a significant sum rate gain as compared to a one-way relaying system as the distance between a relay and the two users decreases. We also show that although we can expand the proposed scheme to more than two users, its performance gain as compared to that of one-way relaying decreases with an increase in the number of users.

Design of 128 point pipelined FFT processor with 4-way structure (4-way 구조를 갖는 128 point 파이프라인 FFT 프로세서의 설계)

  • Lee, Sang-Min;Cho, Un-Sun;Lee, Seong-Joo;Kim, Jae-Seok
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.651-652
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    • 2006
  • In this paper, 4-way data path 128 point pipelined FFT processor with 4-way structure is proposed. The proposed FFT processor has 4-way structure in order to meet data requirement of MB-OFDM system at 132MHz operating frequency. The FFT processor is based on R4MDC and extended to suit 4-way data path. The FFT processor is designed by Verilog HDL and the gate count is about 88k.

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A Study on an Integral State Feedback Controller for Way-point Tracking of an AUV (무인잠수정의 적분 상태 궤환 제어기 설계 및 경유점 추적 연구)

  • Bae, Seol B.;Shin, Dong H.;Park, Sang H.;Joo, Moon G.
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.8
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    • pp.661-666
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    • 2013
  • A state feedback controller with integration of output error is proposed for way-point tracking of an AUV (Autonomous Underwater Vehicle). For the steering control on the XY plane, the proposed controller uses three state variables (sway velocity, yaw rate, heading angle) and the integral of the steering error, and for the depth control on the XZ plane, it uses four state variables (pitch rate, depth, pitch angle) and the integral of the depth error. From the simulation using Matlab/Simulink, we verify that the performance of the proposed controller is satisfactory within an error range of 1m from the target way-point for arbitrarily chosen sets of consecutive way-points.

Fast and Secure 2-Way Handshake Mechanism using Sequence Number in Wireless LAN (순번을 이용한 고속의 안전한 무선 랜 2-Way 핸드쉐이크 기법)

  • Lim, Jeong-Mi
    • Journal of Korea Multimedia Society
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    • v.12 no.9
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    • pp.1323-1332
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    • 2009
  • In this paper, we analyze security weakness of 4-Way Handshake in IEEE 802.11i and propose fast and secure 2-Way Handshake mechanism. Compute PTK(Pairwise Transient Key) using sequence number instead of random numbers in order to protect Replay attack and DoS attack. Also, proposed 2-Way Handshake mechanism can mutual authenticate between mobile station and access point and derive PTK using modified Re-association Request and Re-association Response frames. And, compare with others which are fast and secure Handoff mechanisms.

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An Improved Guidance Algorithm for Smooth Transition at Way-Points in 3D Space for Autonomous Underwater Vehicles

  • Subramanian, Saravanakumar;Thondiyath, Asokan
    • International Journal of Ocean System Engineering
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    • v.2 no.3
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    • pp.139-150
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    • 2012
  • This paper presents an improved guidance algorithm for autonomous underwater vehicles (AUV) in 3D space for generating smoother vehicle turn during the course change at the way-points. The way-point guidance by the line-of-sight (LOS) method has been modified for correcting the reference angles to achieve minimal calculation and smoother transition at the way-points. The algorithm has two phases in which the first phase brings the vehicle to converge to a distance threshold point on the line segment connecting the first two way-points and the next phase generates an angular path with smoother transition at the way-points. Then the desired angles are calculated from the reference and correction angles. The path points are regularly parameterized in the spherical coordinates and mapped to the Cartesian coordinates. The proposed algorithm is found to be simple and can be used for real time implementation. The details of the algorithm and simulation results are presented.

Gait Control on Slope Way using Zero Moment Point for Robot (Zero Moment Point를 이용한 이족 보행 로봇의 경사로 걸음새 제어에 관한 연구)

  • Um, Seung-Hyun;Lim, Mee-Seub;Lim, Joon-Hong
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.530-532
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    • 2006
  • In this paper, we propose stable walking algorithm using ZMP for the biped robot in the slope-way. At first, we define discrete state variables that classified stable area and unstable area by center of mass from ZMP during slope-way walking. For the stable walking gait, the discrete state controller for determining the high-level and low-level decision making are designed. The high-level decision making is composed of the discrete state variables; left foot support phase, right foot support phase, flat-way, and slope-way. Then the continuous state controller is implemented for the low-level decision making using ZMP.

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Feature Extraction for Endoscopic Image by using the Scale Invariant Feature Transform(SIFT) (SIFT를 이용한 내시경 영상에서의 특징점 추출)

  • Oh, J.S.;Kim, H.C.;Kim, H.R.;Koo, J.M.;Kim, M.G.
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.6-8
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    • 2005
  • Study that uses geometrical information in computer vision is lively. Problem that should be preceded is matching problem before studying. Feature point should be extracted for well matching. There are a lot of methods that extract feature point from former days are studied. Because problem does not exist algorithm that is applied for all images, it is a hot water. Specially, it is not easy to find feature point in endoscope image. The big problem can not decide easily a point that is predicted feature point as can know even if see endoscope image as eyes. Also, accuracy of matching problem can be decided after number of feature points is enough and also distributed on whole image. In this paper studied algorithm that can apply to endoscope image. SIFT method displayed excellent performance when compared with alternative way (Affine invariant point detector etc.) in general image but SIFT parameter that used in general image can't apply to endoscope image. The gual of this paper is abstraction of feature point on endoscope image that controlled by contrast threshold and curvature threshold among the parameters for applying SIFT method on endoscope image. Studied about method that feature points can have good distribution and control number of feature point than traditional alternative way by controlling the parameters on experiment result.

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Analysis of the Introspective View of Gutiérrez Alea on the Social Meanings of 'Machismo' in Cuban Society by Focusing on Up to a Certain Point with a Perspective of 'The Viewer's Dialectic' (쿠바 사회에서 마치스모의 사회적 의미 분석 - 구띠에레스 알레아의 관객의 변증법 논점으로 살펴본 <어느 정도까지는>을 중심으로 -)

  • Park, Chong-Wook
    • Iberoamérica
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    • v.13 no.2
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    • pp.71-99
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    • 2011
  • Tomas Gutiérrez Alea, internationally famous cuban director, made the film Up to a certain point with a purpose of criticizing the existence of the extreme male chauvinism as 'machismo' in cuban society of 80's despite of many changes of cultural and social paradigms through 60's and 70's. The director gathered the themes and topics of the films like Lucia, One way or another, and Teresa's portrait and analyzed them to present alternatives. The way of approaching to solve that kind of social problems that Alea proposed to the spectator is taking time to think of the problems with a way of "The Viewer's Dialectic". Identification with the protagonist of the film(thesis) and alienation from him(antithesis) could make the audience generalize the diverse aspects of the problem and then one might get an insight(synthesis) to live the life with more satisfaction that is supposed to be a social function of the film as arts according to the director of the film Up to a certain point.