• Title/Summary/Keyword: Mobile surface

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A Development of Stereo Camera based on Mobile Road Surface Condition Detection System (스테레오카메라 기반 이동식 노면정보 검지시스템 개발에 관한 연구)

  • Kim, Jonghoon;Kim, Youngmin;Baik, Namcheol;Won, Jaemoo
    • International Journal of Highway Engineering
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    • v.15 no.5
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    • pp.177-185
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    • 2013
  • PURPOSES : This study attempts to design and establish the road surface condition detection system by using the image processing that is expected to help implement the low-cost and high-efficiency road information detection system by examining technology trends in the field of road surface condition information detection and related case studies. METHODS : Adapted visual information collecting method(setting a stereo camera outside of the vehicle) and visual information algorithm(transform a Wavelet Transform, using the K-means clustering) Experiments and Analysis on Real-road, just as four states(Dry, Wet, Snow, Ice). RESULTS : Test results showed that detection rate of 95% or more was found under the wet road surface, and the detection rate of 85% or more in snowy road surface. However, the low detection rate of 30% was found under the icy road surface. CONCLUSIONS : As a method to improve the detection rate of the mobile road surface condition information detection system developed in this study, more accurate phase analysis in the image processing process was needed. If periodic synchronization through automatic settings of the camera according to weather or ambient light was not made at the time of image acquisition, a significant change in the values of polarization coefficients occurs.

A Study on Development of a Reconfigurable Mobile Robot and Dead-Reckoning Using Extended Kalman Filter (가변구조형 주행로봇 개발 및 확장형 칼만필터를 이용한 추측 항법에 대한 연구)

  • Kang, Bong-Soo;Yeo, Gee-Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.5
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    • pp.455-462
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    • 2009
  • This paper presents design concepts of a reconfigurable mobile robot for both of indoor and outdoor applications. A linkage mechanism and wheel-in-motors give the proposed mobile robot various driving modes in maneuver and good adaptability to irregular surface. Since the mobile robot receives multiple sensor signals from odometers and an orientation sensor, states related to the position and the orientation of the mobile robot are optimally estimated by an extended Kalman filter. Simulations and experimental results show that the performance of dead reckoning on estimating the pose of a mobile robot can be improved remarkably by the optimal state observer.

Development of Mobile 3D Terrain Viewer with Texture Mapping of Satellite Images

  • Kim, Seung-Yub;Lee, Ki-Won
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.351-356
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    • 2006
  • Based on current practical needs for geo-spatial information on mobile platform, the main theme of this study is a design and implementation of dynamic 3D terrain rendering system using spaceborne imagery, as a kind of texture image for photo-realistic 3D scene generation on mobile environment. Image processing and 3D graphic techniques and algorithms, such as TIN-based vertex generation with regular spacing elevation data for generating 3D terrain surface, image tiling and image-vertex texturing in order to resolve limited resource of mobile devices, were applied and implemented by using graphic pipeline of OpenGL|ES (Embedded System) API. Through this implementation and its tested results with actual data sets of DEM and satellite imagery, we demonstrated the realizable possibility and adaptation of complex typed and large sized 3D geo-spatial information in mobile devices. This prototype system can be used to mobile 3D applications with DEM and satellite imagery in near future.

Uncertainty for Privacy and 2-Dimensional Range Query Distortion

  • Sioutas, Spyros;Magkos, Emmanouil;Karydis, Ioannis;Verykios, Vassilios S.
    • Journal of Computing Science and Engineering
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    • v.5 no.3
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    • pp.210-222
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    • 2011
  • In this work, we study the problem of privacy-preservation data publishing in moving objects databases. In particular, the trajectory of a mobile user in a plane is no longer a polyline in a two-dimensional space, instead it is a two-dimensional surface of fixed width $2A_{min}$, where $A_{min}$ defines the semi-diameter of the minimum spatial circular extent that must replace the real location of the mobile user on the XY-plane, in the anonymized (kNN) request. The desired anonymity is not achieved and the entire system becomes vulnerable to attackers, since a malicious attacker can observe that during the time, many of the neighbors' ids change, except for a small number of users. Thus, we reinforce the privacy model by clustering the mobile users according to their motion patterns in (u, ${\theta}$) plane, where u and ${\theta}$ define the velocity measure and the motion direction (angle) respectively. In this case, the anonymized (kNN) request looks up neighbors, who belong to the same cluster with the mobile requester in (u, ${\theta}$) space: Thus, we know that the trajectory of the k-anonymous mobile user is within this surface, but we do not know exactly where. We transform the surface's boundary poly-lines to dual points and we focus on the information distortion introduced by this space translation. We develop a set of efficient spatiotemporal access methods and we experimentally measure the impact of information distortion by comparing the performance results of the same spatiotemporal range queries executed on the original database and on the anonymized one.

A Modified Adsorption Model for Retention of Nonpolar Solutes in Reversed Phase Liquid Chromatography

  • Cheong Won Jo
    • Bulletin of the Korean Chemical Society
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    • v.15 no.1
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    • pp.15-20
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    • 1994
  • The adsorption model in reversed phase liquid chromatography has been critically examined. It has been found that use of the Everett type surface activity coefficient for the solute in the stationary phase is not useful to study the retention characteristics of a nonpolar solute. We suggest a modified model. In this model it is assumed that the displaced modifier molecules from the surface monolayer do not transfer into the bulk mobile phase but stick to the nonpolar solute which has displaced them. In addition, we prefer to use an apparent stationary phase activity coefficient of the soluie instead of the Everett type activity coefficient. This modified adsorption model well explains the mobile and stationary phase effects on the solute retention upon variation of mobile phase composition.

Double Sliding Surfaces based on a Sliding Mode Control for a Tracking Control of Mobile Robots (이동 로봇의 추종 제어를 위한 이중 슬라이딩 표면에 기반한 슬라이딩 모드 제어)

  • Lee, Jun Ku;Choi, Yoon Ho;Park, Jin Bae
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.6
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    • pp.495-500
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    • 2013
  • This paper proposes a double sliding surfaces based on a sliding mode control for a tracking control of nonholonomic mobile robots in the Cartesian coordinates. In order to remove sliding surface constraints, we design the additional sliding surface for the heading angle with respect to the newly defined coordinates. Then, we define the switching law based on the posture error to combine the designed sliding surface with the previous one. By using the double sliding surfaces and the switching law, we obtain the control law for arbitrary trajectories. It is proved that the position tracking error and the heading direction error asymptotically converge to zero, respectively, with the Lyapunov stability theory. Finally, through computer simulations, we demonstrate the effectiveness of the proposed control system.

Robust Control Design for a Two-Wheeled Inverted Pendulum Mobile Robot (이륜 도립진자 이동로봇을 위한 강인제어기 설계)

  • Yoo, Dong Sang
    • Journal of the Korean Institute of Intelligent Systems
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    • v.26 no.1
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    • pp.16-22
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    • 2016
  • The research on two-wheeled inverted pendulum (TWIP) mobile robots has been ongoing in a number of robotic laboratories around the world. In this paper, we consider a robust controller design for the TWIP mobile robot driving on uniform slopes. We use a 2 degree-of-freedom (DOF) model which is obtained by restricting the spinning motion in a 3 DOF motion dynamic equation. In order to design the robust controller guaranteeing stability of the TWIP mobile robot driving on inclined surface, we propose a sliding mode control based on the theory of variable structure systems and design a sliding surface using the theory of the linear quadratic regulation (LQR). For simulation, the dynamic model of the TWIP mobile robot is constructed using Mathworks' Simulink and the sliding mode control is also implemented using Simulink. From simulation results, we show that the proposed controller effectively controls the TWIP mobile robot driving on slopes.

The Mobile Robot Localizaion Using a Single Sonalr and Cylindrical Beacon (초음파 센서와 실린더형 등대를 이용한 이동 로봇의 위치 추정)

  • 범희락;조형석
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.10a
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    • pp.570-574
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    • 1993
  • This paper proposes a new method of estimating the position and heading angle of a mobile robot moving on a flat surface. The proposed localization method utilizes two passive beacons and a single rotating ultrasonic sensor. The passive beacons consist of two cylinders with different diameters and reflect the ultrasonic pulses coming from the sonar sensor mounted on the mobile robot. The geometric parameter set of beacon is acquired from the sonar scan data obtained at a single mobile robot location using a new data processing algorithm. Form this parameter set, the position and heading angle of the mobile robot is determined directly. The performance and validity of the proposed method are evaluated using two beacons and a single sonar sensor attached at the pan-tilt device mounted on a mobile robot, named LCAR, in our laboratory.

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Development of the FishBowl Game Employing a Tabletop Tiled Display Coupling With Mobile Interfaces (모바일 인터페이스와 테이블탑 타일드 디스플레이를 연동한 FishBowl 게임 개발)

  • Kong, Young-Sik;Park, Kyoung-Shin
    • Journal of Korea Game Society
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    • v.10 no.2
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    • pp.57-66
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    • 2010
  • In the prior works on tabletop systems, a projection-based tabletop surface is mostly used to display computer images, and the participants interact with the display surface by hand multi-touching or using some tangible objects. In this research, however, we developed the FishBowl game that employs a scalable tabletop tiled display with infrared camera tracking coupled with PDA mobile interfaces. The focus of this game is to enhance user interactivity and realistic experience by coupling the high-resolution tabletop virtual environment and PDA mobile interface. This paper describes the game design followed by the system design and its detailed implementations. It also discusses the system usability and recommendation for its improvements after interviewing game players and then concludes with future research directions.