• Journal of Advanced Marine Engineering and Technology
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• v.37 no.6
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• pp.644-652
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• 2013

This paper describes the development and field experiments of Manta-type Unmanned Underwater Vehicle (UUV). Various simulations for Manta UUV are performed by using the nonlinear 6-DOF motion of equations. Through this simulation we verified the motion performances of Manta UUV. To acquire the blueprint of Manta UUV, it was designed with the simulation results. The Manta UUV uses a Doppler Velocity Log (DVL), gyrocompass, GPS, pressure sensor and other minor sensors, applied to measure the motion, position and path of Manta UUV. For its propulsion and changing a direction in the underwater, one vertical fin and four horizontal fins are installed at the hull of UUV. The Manta UUV system was verified with motion and autonomous navigation test at field.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.971-980
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• 2010

In this paper, we present a navigation control algorithm for mobile robots that move in environments having static and moving obstacles. The algorithm includes a global and a local path-planning algorithm that uses $D^*$ search algorithm, a fuzzy logic for determining the immediate level of danger due to collision, and a fuzzy logic for evaluating the required wheel velocities of the mobile robot. To apply the $D^*$ search algorithm, the two-dimensional space that the robot moves in is decomposed into small rectangular cells. The algorithm is verified by performing simulations using the Python programming language as well as by using the dynamic equations for a two-wheeled mobile robot. The simulation results show that the algorithm can be used to move the robot successfully to reach the goal position, while avoiding moving and unknown static obstacles.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.4
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• pp.675-683
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• 1992

Mapping and navigation system based on certainty grids for an autonomous mobile robt operating in unknown and unstructured environment is described. The system uses sonar range data to build a map of robot's surroundings. The range data from sonar sensor are integrated into a probability map that is composed of two dimensional grids which contain the probabilities of being occupied by the objects in the environment. A Bayesian model is used to estimate the uncertainty of the sensor information and to update the existing probability map with new range data. The resulting two dimensional map is used for path planning and navigation. In this paper, the Bayesian updating model which was successfully simulated in our earlier work is implemented on a mobile robot and is shown to be valid in the real world through experiment. This paper also proposes a technique for reducing for reducing specular reflection problem of sonar system which seriousely deteriorates the map quality, and a new path planning method based on weighted distance, which enables the robot to efficiently navigate in an unknown area.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.457-466
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• 2011

In general, drivers need a self-interest information to decide their routes. So, non-governmental sectors, such as Internet Portal Company, make and provide user-oriented contents for drivers in a hurry. But, VMS which is the typical public media always provides traffic-information for drivers without weighting personal characteristics and considering transportation conditions. So in this research, we searched importance and preference of traffic-information contents as IPA(Importance-Performance Analysis)result. We can draw the conclusion that the improvement of traffic-information contents focused on users(drivers) is needed. Specially, we proposed the strategy of VMS according to traffic conditions.

• Journal of Broadcast Engineering
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• v.25 no.5
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• pp.734-741
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• 2020

This article proposes a new pedestrian avoidance algorithm for social robots that coexist and communicate with humans and do not induce stress caused by invasion of psychological safety distance(Social Distance). To redefine the pedestrian model, pedestrians are clustered according to the pedestrian's gait characteristics(straightness, speed) and a social distance is defined for each pedestrian cluster. After modeling pedestrians(obstacles) with the social distances, integrated navigation algorithm is completed by applying the newly defined pedestrian model to commercial obstacle avoidance and path planning algorithms. To show the effectiveness of the proposed algorithm, two commercial obstacle avoidance & path planning algorithms(the Dynamic Window Approach (DWA) algorithm and the Timed Elastic Bands (TEB) algorithm) are used. Four cases were experimented in applying and non-applying the new pedestrian model, respectively. Simulation results show that the proposed algorithm can significantly reduce the stress index of pedestrians without loss of traveling time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10B
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• pp.883-890
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• 2006

The study of sensor network database is beginning to liven up as we are interested in Ubiquitous Computing technology in hardware, communication, database and so on. Especially, as new smart sensors have capabilities of real-time information gathering and analysis of each sensor node, data processing becomes an important issue in Ubiquitous Computing. In thesis, we have applied TinyDB(query processing system) to carry sensor node with line tracer which can follow the fixed path. After we gathered data around path, we have processed data in TinyDB GUI, gathered data, displayed data on a web server. Also we have a web browser on an embedded board for convenient user interface and implemented touch screen such that users can operate with a finger.

• Korean Journal of Head & Neck Oncology
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• v.7 no.1
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• pp.52-56
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• 1991

인체에서 발견되는 전체 신경초종중 $25{\sim}40%$가 두경부에서 발견되나 경부미주신경의 신경초종은 매우 희귀하여 1988년까지 영문문헌상 88 예가 보고되어 있다. 임상적으로 경부종괴가 주증상이며 때로는 애성, 종괴촉지시 기침 혹은 방사통, parapharyngeal space 의 종괴성장으로 연하곤란등이 초래되기도 한다. 치료는 종괴의 완전적출과 미주신경의 기능을 보존시키는 것이 주요 목표로 되어 있다. 저자들은 최근 5년간 4 예의 정부미주신경외 신경초종을 경험하였는데, 3 예는 측경부의 상부에, 1예는 측경부의 하부에 발생한 것이었다. 연령은 25세에서 50세까지 성인연령이었고, 성별은 남자 l 예, 여자 3 예이었다. 내원시 주소는 전예가 무통성 경부종괴이었으며, 종괴의 크기는 직경 3cm에서 10cm까지 다양하였다. 전예에서 종괴로 인한 신경학적 증상은 없었으나, 1 예에서 parapharyngeal space 의 거대종괴 때문에 다소간의 연하곤란이 있었다. 2 에에서는 종괴촉지시 기침이 유발됨을 호소하였다. 수술은 경부횡절개로 흉쇄유돌근을 제치고 총경 동맥과 내경정맥을 종괴의 상하부위가 완전히 노출되도록 박리한 후 종괴의 피막을 미주 신경의 주행방향에 따라 절개하여 적출 (enucleation) 하였다. 적출술시 종괴가 유착되어 있는 피막 부위는 동시에 절제하되 미주신경의 신경경로 (neural pathway) 는 유지되도록 하였다. 수술직후 2 예에서 일시적 애성을 호소하였다, 추적은 최단 20 개월에서 최장 80 개월까지 하였는데 일시적 애성은 호전되었고 전예가 재발없이 건강하게 지내고 있었다. 따라서 본 종양수술은 종양적출술시 이환된 미주신경의 절단을 결정하기 전에 신경경로를 유지시킬 수 있는 적출술 (enucleation) 을 먼저 고려하는 것이 바람직하다고 사료되었다.

• Spatial Information Research
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• v.21 no.6
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• pp.57-67
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• 2013

GPS based car navigation systems show significant problems in such environment as a tunnel, a road surrounded by high buildings. In this study, we thus propose a method to determine positions and attitudes using only in-vehicle sensory data without a GPS. To check the feasibility of this method, we constructed a system to acquire in-vehicle sensory data and reference data simultaneously. We acquired test data using this system, estimated the trajectory based on the proposed method and evaluated the accuracy of both the sensory data and the trajectory. The speed and angular velocities provided by the in-vehicle sensors include 1.1 km/h and 0.8 deg/s RMS errors, respectively. The estimated trajectory using these data shows 20.8 m RMS errors for a 15 minute drive. In future, if we further combine additional sensors such as a camera and a GPS, we can achieve a high accurate navigation system at a low cost without an expensive high-grade external IMU.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.6
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• pp.1441-1446
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• 2014

For the escape from a maze, the cooperative method by robot swarm was proposed in this paper. The robots can freely move by collecting essential data and making a decision in the use of sensors; however, a central control system is required to organize all robots for the escape from the maze. The robots explore new mazes and then send the information to the system for analyzing and mapping the escaping route. Three issues were considered as follows for the effective escape by multiple robots from the mazes in this paper. In the first, the mazes began to divide and secondly, dead-ends should be blocked. Finally, after the first arrivals at the destination, a shortcut should be provided for rapid escaping from the maze. The parallel-escape algorithms were applied to the different size of mazes, so that robot swarm can effectively get away the mazes.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.219-230
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• 2017

This paper proposes a vehicle to road tracking algorithm based on vision sensor by using EKF(Extended Kalman Filter). The lateral offset, heading angle, and curvature which are obtained from vehicle to road tracking might be used as inputs to steering controller of LKAS(Lane Keeping Assist System) or for the warning decision logic of LDWS(Lane Departure Warning System). To the end, in this paper, the yaw rate, steering angle, and vehicle speed as well as lane raw points together with considering of vehicle lateral dynamics are utilized to improve the exactness and convergence of the vehicle to road tracking. The proposed algorithm has been tested at a proving ground that consists of straight and curve sections and compared with GPS datum using DGPS-RTK equipment to show the feasibility of the proposed algorithm.