• International Journal of Railway
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• v.3 no.3
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• pp.106-112
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• 2010

Accidents at level crossing have large portion on train accidents, and causes economical loss by train delay and operational interruption. Various safety equipments are employed to reduce the accident at level crossing, but existing warning device, and crossing barrier are simple train-oriented protection equipments. In this paper, intelligent railway level crossing system is proposed to prevent and reduce accidents. For train driver's prompt action, image of level crossing and obstacle warning message are continuously provided to train driver through wireless communication in level crossing control zone. Obstacle warning messages, which are extracted by computer vision processing of captured image at level crossing, are recognized by train driver through message color, flickering and warning sound. It helps train driver to decide how to take an action. Meanwhile, for vehicle driver's attention, location and speed of approaching train are given to roadside equipments. We identified the effect of proposed system through test installation at Sea train and Airport level crossing of Yeong-dong line.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1930-1936
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• 2010

Because of the environmental matters the importance of the city railroad is as time goes by increasing. The case of obstacle of the power equipment which supplies electric power to city railroad will occur social and economical enormous loss. Thus, I studied on the preventing method in advance which makes it possible for us to maintain facilities efficiently. The main check points of the power facilities are voltage, current, humidity, partial discharge, move current. These points are gathered by sensor and transmitting to data acquisition device. These data are used to check equipment status in real time. In this paper I described in brief test process and results of the detection system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.95-95
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• 2010

Because of the environmental matters the importance of the city railroad is as time goes by increasing. The case of obstacle of the power equipment which supplies electric power to city railroad will occur social and economical enormous loss. Thus, I studied on the preventing method in advance which makes it possible for us to maintain facilities efficiently. The main check points of the power facilities are voltage, current, humidity, partial discharge, move current. These points are gathered by sensor and transmitting to data acquisition device. These data are used to check equipment status in real time. In this paper I described in brief test process and results of the detection system.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.2
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• pp.111-116
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• 2014

Using only laser range finder to detect the obstacles in an environment that contains transparent obstacles can not guarantee autonomous mobile robot from collision problem. To solve this problem, a mobile robot using laser range finder must be used additional sensor device such as sonar sensor that can detect the transparent obstacle. In this paper, a method is addressed to deal with the problem to detect the transparent obstacles within environment only by using laser range finder for mobile robot. In case the recognized transparent obstacle, the proposed algorithm is to localize the transparent obstacle to extract and process the reflected noise. This algorithm ensures autonomous of mobile robot only using laser range finder. The effectiveness of the proposed algorithm is evaluated by the real mobile robot and real laser range finder experiments with three case studies.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.23 no.4
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• pp.37-53
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• 2024

This study selected bicycle road hazard detection factors for mobile IoT sensor device operation and developed service application plans. Twelve bicycle road hazard detection factors were derived through a focused group interview, and a fuzzy AHP-based importance analysis was conducted on 30 road and transportation experts. As a result, 'damage to pavement' (1st overall) and 'environmental obstacle' (2nd) with low visibility but a high risk of accidents were selected the most. The factors in terms of facility management, such as 'disconnected route occurrence' (4th), 'artificial obstacle' (5th), 'effective width' (6th), and 'poor drainage' (7th), were selected as the upper and middle areas. Factors that are not direct accident-inducing factors, such as 'loss of road markings' (11th) and 'free space width' (12th), were selected the least. Based on this, a plan was presented to apply the bicycle road hazard detection service and a service operation strategy according to real-time performance. Nevertheless, follow-up studies, such as human behavioral analysis based on bicycle operators, analysis according to the bicycle road type, service demonstration, and pilot operation, will be needed to develop safe bicycle road management is expected.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.4
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• pp.167-174
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• 2002

This study describes a fetal heart rate(FHR) estimation algorithm using phonogram. Using a phonogram amplifier, various fetal heart sounds are collected in a university hospital. The FHR estimation algorithms consists of a lowpass filter, decimation, envelop detection, pitch detection, and post-processing. The post-processing is the FHR decision procedure using all informations of fetal heart rates. Using the algorithm and other parameters of fetal heart sound, a fetal monitoring software was developed. This can display the original signals, the FFT spectra, FHR and its trajectory. Even though the fetal phonogram amplifier detects the fetal heart sounds well, the sound quality is not so good as the ultrasonography. In case of very week fetal heart sound, autocorrelation of it showed clear periodicity. But two main peaks in one period is an obstacle in pitch detection and peaks are not so vivid. The proposed FHR estimation algorithm showed very accurate and stable results. Since the developed software displays multiple parameters in real time and has convenient functions, it will be useful for the phonogram-style fetal monitoring device.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.11
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• pp.1653-1659
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• 2022

Virtual reality content provides users with a high sense of immersion by using HMD devices. However, while wearing the HMD device, it is difficult to determine the user's location or distance from obstacles, resulting in injuries due to physical collisions. In this paper, we propose a reminder module to prevent accidents by notifying the risk of collision with obstacles while wearing the HMD device. The proposed module receives the user's state from the acceleration and gyro sensor and determines the motion that is likely to cause a collision. If there is an obstacle in the expected collision range, a buzzer sounds to the wearer. As a result of the experiment, the accuracy of obstacle detection in the state of wearing the HMD was 86.6% in the 1st stage and 83.3% in the 2nd stage, confirming the performance of the accident prevention reminder.

• Journal of Internet Computing and Services
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• v.15 no.6
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• pp.117-124
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• 2014

Cluttered background is a major obstacle in developing salient object detection and tracking system for mobile device captured natural scene video frames. In this paper we propose a context aware feature vector selection model to provide an efficient noise filtering by machine learning based classifiers. Since the context awareness for feature selection is achieved by searching nearest neighborhoods, known as NP hard problem, we apply a fast approximation method with complexity analysis in details. Separability enhancement in feature vector space by adding the context aware feature subsets is studied rigorously using principal component analysis (PCA). Overall performance enhancement is quantified by the statistical measures in terms of the various machine learning models including MLP, SVM, Naïve Bayesian, CART. Summary of computational costs and performance enhancement is also presented.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.418-420
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• 2005

This paper proposed ultrasonic distance measurement module development for correct distance detection with collision escaping or obstacle of mobile robot is traveling self-regulation. Representative ultrasonic module applied in existing was Polaroid company's 6500 series and Devantech company's SRF04/SRF08 series. This ultrasonic sensors are corrupted by systematic errors due mainly to the dependency of sound speed upon surrounding conditions and random errors of uncertain origin. Therefore Ultrasonic distance detecting means of error compensation method and high definition, narrow beam angle, board area distance detecting means to apply to ultrasonic mobile robot control urgently need. In this paper use internal type temperature compensation method to improve problem of ultrasonic distance measurement method instead of that volume that have shortcoming of used correct temperature compensation methods applied big addition device. Compensate error by environment change of temperature. Humidity density etc. and is applicable to mobile robot offering various interface and real-time processing developed possible distance measurement module.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.12
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• pp.65-74
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• 2008

This paper deals with the path creation for stable action of a robot and transformation by using the fuzzy algorithm. Also, the obstacle detection and environmental analysis are performed by a stereo vision device. The robot decides the range and the height using the fuzzy algorithm. Therefore the robot can be adapted in topography through a transformation by itself. In this paper, the robot is designed to have two advantages. One is the fast movability in flat topography with the use of wheels. The other is the moving capability in uneven ground by walking. It has six leg forms for a stable walk. The wheels are fixed on the legs of the robot, so that various driving is possible. The height and the width of robot can be changed variously using four joints of each leg. The wheeled joint has extra DOF for a rotation of vertical axis. So the robot is able to rotate through 360 degrees. The robot has various sensors for checking the own state. The stable action of a robot is achieved by using sensors. We verified the result of research through an experiment.