• The Journal of the Korea Contents Association
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• v.11 no.4
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• pp.18-26
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• 2011

According that smart phones have been widely used, their users can easily access various information around the devices through location information services equipped to the smart phone devices. In this paper, we propose a WeWhere which is a system of client-server model for providing the current location among several smart phone users in real time. A client-side smartphone user send to a server his/her current location obtained by applying location information service provided from smart phones and receive location information of all smartphone users connected to the user from the server. The all location information is displayed on a smartphone of a user in client-side and users can track location of their related users. All most 200,000 persons in the world have used the proposed system, WeWhere, normally without overloading of a server system.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.1
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• pp.49-56
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• 2014

In this study, the generation efficiency of the limited area of a concentrator solar cell was increased by using a solar concentrator and a tracking device. Heat generated by the solar cell was collected using a thermal absorber for supplying hot water or heating. Thus, the concentrator solar cell system provided electricity and heat simultaneously. Tracking of the sun by detecting the sun's position, repositioning of heating device towards the east after sunset, and shutting down of system after sunset were successfully implemented using an illuminance sensor (CdS) and Simulink, a commercial software package. We performed parametric analysis of the velocity, fin installation, and entrance location with respect to the operating temperature of the concentrator solar cell. A heat transfer simulation model was developed for comparing the actual temperature profiles of the concentrator solar cell and thermal absorber, and good agreement was found between the results of the simulations and the experiments.

• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.57-64
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• 2014

Recently, many human-friendly communication methods have been studied for human-machine interface(HMI) without using any physical devices. One of them is the vision-based gesture recognition that this paper deals with. In this paper, we define some gestures for interaction with objects in a predefined virtual world, and propose an efficient method to recognize them. For preprocessing, we detect and track the both hands, and extract their silhouettes from the low-resolution hand images captured by a webcam. We modeled skin color by two Gaussian distributions in RGB color space and use blob-matching method to detect and track the hands. Applying the foodfill algorithm we extracted hand silhouettes and recognize the hand shapes of Thumb-Up, Palm and Cross by detecting and analyzing their modes. Then, with analyzing the context of hand movement, we recognized five predefined one-hand or both-hand gestures. Assuming that one main user shows up for accurate hand detection, the proposed gesture recognition method has been proved its efficiency and accuracy in many real-time demos.

• The Journal of the Korea Contents Association
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• v.10 no.10
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• pp.111-119
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• 2010

This paper deals with the experiments of optokinetic differentiation within eye tracking test through the menu direction and cognitive degree of service menu title for watching digital media service. Researcher establish a research topic which verification of differentiations of eye tracking velocity when media user perceive the service menu title within vertical structure or horizontal structure. Experimentation was designed with two types of menu structure-vertical or horizontal-and these have each 9 cases of eye tracking tasks for experimentee. Researcher arrives at a conclusion through as stated above experiment that cases of vertical menu structure is more effective method with linear channel service menu, otherwise that cases of horizontal menu structure is more effective method with non linear channel service menu, like a video on demand service. The research results will be very helpful with actual media industry players when they planning the evolutionary direction of their menu layout.

• Journal of Korea Multimedia Society
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• v.8 no.10
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• pp.1293-1305
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• 2005

In this paper, we propose the method of manipulating the gaze direction of 3D FPS game's character by using eye gaze detection from the successive images captured by USB camera, which is attached beneath HMD. The proposed method is composed of 3 parts. In the first fart, we detect user's pupil center by real-time image processing algorithm from the successive input images. In the second part of calibration, the geometric relationship is determined between the monitor gazing position and the detected eye position gazing at the monitor position. In the last fart, the final gaze position on the HMB monitor is tracked and the 3D view in game is control]ed by the gaze position based on the calibration information. Experimental results show that our method can be used for the handicapped game player who cannot use his (or her) hand. Also, it can increase the interest and immersion by synchronizing the gaze direction of game player and that of game character.

• Journal of Korea Multimedia Society
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• v.15 no.11
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• pp.1319-1329
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• 2012

AGVs are more and more utilized nowadays and magnetic guided AGVs are most widely used because their system has low cost and high speed. But this type of AGVs requires high infrastructure building cost and has poor flexibility of navigation path layout changing. Thus it is hard to applying this type of AGVs to a small quantity batch production system or a cooperative production system with many AGVs. In this paper, we propose a vision based guideline interpretation technique that uses the cheap, easily installable and changeable color tapes (or paint) as a guideline. So a vision-based AGV with color tapes is effectively applicable to the production systems. For easy setting and changing of AGV navigation path, we suggest an automatic method for interpreting a complex guideline layout including multi-branches and joins of branches. We also suggest a trace direction decision method for stable navigation of AGVs. Through several real-time navigation tests with an industrial AGV installed with the suggested technique, we confirmed that the technique is practically and stably applicable to real industrial field.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.545-552
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• 2012

In this paper, we propose Modified Multi CAMShift Algorithm based on Kalman filter and Weighted Search Windows(KWMCAMShift) that extracts skin color area and tracks several human body parts for real-time human tracking system. We propose modified CAMShift algorithm that generates background model, extracts skin area of hands and head, and tracks the body parts. Kalman filter stabilizes tracking search window of skin area due to changing skin area in consecutive frames. Each occlusion areas is avoided by using weighted window of non-search areas and main-search area. And shadows are eliminated from background model and intensity of shadow. The proposed KWMCAMShift algorithm can estimate human pose in real-time and achieves 96.82% accuracy even in the case of occlusions.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.633-639
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• 2007

This study proposes an optimal condition to recognize a train using RFID. In order to recognize a moving train, bandwidth, an angle of antenna and the location of a tag should be considered. In this study, a field test was conducted using two different bandwidths (900MHz and 2.45GHz), four angles of antenna(0, 30, 45, and $60^{\circ}$), different velocities (10, 30 and 50km), and three different locations of tags. The field test verified the optimal condition for recognition of a train, The present study convinced that location detection and tracking of rail freight can be monitored in real time. The present technology can be applied to railway signals including detecting and tracking such as EURO Balis.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.187-195
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• 2018

In this study, using real-time gaze tracking and head tracking method, we intended to quantitatively evaluate the deviation between the patient's head and gaze direction while minimizing inspection errors due to apraxia of conventional paper-based examination respectively. As a result, we developed a software that can quantitatively measure gaze and head movement information, and computerized the line bisection and star cancelation test, which are generally used as conventional paper test. In addition, for the rehabilitation training, contents corresponding to the visual technology of Warren's visual hierarchical model lower level are implemented and can be performed repetitively and independently. This allows the patient to actively participate in rehabilitation and quantitatively compare the degree of improvement.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.4
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• pp.11-21
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• 2000

This paper proposes a new algorithm for a mobile robot that detects and tracks a moving target, keeping it in the view range of the robot. The sensor system consists of a camera and a line light source. The camera system is placed so that the line light projected into the ground from the light source forms its image along the horizontal center line of the CCD array of the camera. The deformation of the line image from the horizontal center line contains the information on existence of a moving object, its velocity, and position. Since the proposed algorithm reduces the region of the image to be searched, it reduces the computational complexity significantly comparing to the conventional image processing algorithms. The performance of the proposed algorithm has been tested by implementing on a mobile robot.