• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.3
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• pp.27-33
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• 2012

Tele-presence and tele-operation techniques are used to build up an immersive scene and control environment for the distant user. This paper presents a novel tele-presence system using the camera tracking based on planar homography. In the first step, the user wears the HMD(head mounted display) with the camera and his/her head motion is estimated. From the panoramic image by the omni-directional camera mounted on the mobile robot, a viewing image by the user is generated and displayed through HMD. The homography of 3D plane with markers is used to obtain the head motion of the user. For the performance evaluation, the camera tracking results by ARToolkit and the homography based method are compared with the really measured positions of the camera.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.8
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• pp.837-848
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• 2014

This paper describes the development of a walking assistive robot for effective self-rehabilitation for elderly people facing an inconvenience in walking. The main features of the developed robot are enhanced safety and mobility using the baby walker and electric wheelchair mechanisms and an accurate walking tracking control algorithm using potentiometers and stereo cameras. Specifically, a pelvis supporter is designed to prevent the user from falling down and reduce the burden on their legs, and electric motors are used for easy locomotion with low effort. Next, the walking intention and direction of the user are automatically recognized by using potentiometers attached at the pelvis supporter so that the robot can track the user, and the rapidity and accuracy of the tracking were increased by applying a lower-body motion analysis algorithm with stereo cameras. Finally, the user-tracking performance of the developed robot was experimentally verified through stepwise walking assistance experiments.

• Journal of Advanced Navigation Technology
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• v.19 no.1
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• pp.74-79
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• 2015

In this paper, in order to improve the error is utilized to location tracking the smart sensor detects a walking information user, RSSI is to provide an indoor position tracking system that is capable of correcting an error in terms weak. The acceleration sensor is able to detect the activity in the user walking and detects the number of step and the moving distance using the same. The Direction sensor is utilized as a digital compass, to detect the moving direction of the user. As a result of detecting the walking information using the sensor, it can be showed that this proposed indoor positioning system has a high degree of accuracy for the number of steps and the movement direction. Therefore, this paper shows that the proposed technique can correct the error of the location information to be problem in the conventional indoor location system which uses the only Wi-Fi APs by estimating the user's movement direction and distance using the sensors in smartphone without an additional equipment and cost.

• Archives of design research
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• v.16 no.4
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• pp.197-206
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• 2003

Nowadays, the studies on interface and cognition-engineering has become issues of general interest as newly design-methods which analyze the behavior of user on products. However existing studies were mainly done with verbal-centered method which made it difficult for the designer to apply for visual realization. Moreover many mistakes and noises are taken place whenever the designer converts verbal statements and needs of user into visual factors. Therefore the designer needs to analyze visual perception on user and product as visual-centered methods. This study applies the eye tracking method as analysing-instrument and aims to develop the analysis-framework, the concrete techniques of measurement and the application for the product design. At first the nature and the process of visual perception on products are reviewed for developing analysis method. Then the technique of eye tracking and the meaning of fixation and movement are discussed to specify the concrete method. The basic experiment of product can reveal general analysis process, advantage and guideline for the application of eye tracking method. The Study is peformed through the following 4 steps ; to pre-research into product design and visual perception theory ; to identify the concrete experiment method, to measure the fixation/movement data and analyze the raw data, to convert the result of analysis to the visual framework. Finally the major findings and the limits of the study are suggested and summarized.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1046-1050
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• 2003

In general, conventional user identification systems require users to carry a TAG or badge or to remember ID and password. Though biometric identification systems may relieve these problems, they are susceptible to environmental noise to some degree. We propose a natural user identification system, ubiFloor, exploiting user's walking pattern to identify the user. The system identifies a user, while tracking the user's location, with a set of simple ON/OFF switch sensors or equipments. Experimental results show that the proposed system can recognize the registered users at the rate of 92%. Future improvement in recognition rate may be achieved by combining other sensors such as camera, microphone, etc.

• Asia pacific journal of information systems
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• v.14 no.3
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• pp.121-144
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• 2004

Developing a personalized system on a user's behalf which is working around the Internet-based marketplace is one of the challenging issues in intelligent e-business, especially mobile commenrce. It has been highly recommended that such a mobile personalized system has to perceive the user's needs a priori by tracking user's current context such as location with activity and then to identify the current needs dynamically and proactively. Automatically and unobtrusively getting user's context is an inevitable feature for the development of autonomous mobile commenrce. However, personalization methodologies and their feasible architectures for context-aware mobile commerce have been so far very rare. Hence, this paper aims to propose a context-aware mobile commerce development methodology by applying agent and semantic web technologies for personalized reminder system, which is one of the mobile commerce support system. We revisited associationism to understand a buyer's need identification process and adopt the process as 'purchase based on association' to implement a personalized reminder system. Based on this approach, we have showed how the agent-based semantic web service system can be used to realize need-aware reminder system. NAMA(Need-Aware Multi-Agent), a prototype system, has been implemented to show the feasibility of the methodology and framework under mobile setting proposed in this paper. NAMA embeds bluetooth-based location tracking module and identify what a user is currently looking at through her/his mobile device such as PDA. Based on these capabilities, NAMA considers the context, user profile with preferences, and information about currently available services, to aware user's current needs and then link her/him to a set of services, which are implemented as web services.

• Journal of the Korean Solar Energy Society
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• v.36 no.6
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• pp.47-59
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• 2016

As the usage of sun tracking system in solar energy utilization facility increases, requirement of more accurate computation of sun position has also been increased. Accordingly, various algorithms to compute the sun position have been proposed in the literature and some of them insist that their algorithms guarantee less than 0.01 degree computational error. However, mostly, the true meaning of accuracy argued in their publication is not clearly explained. In addition to that, they do not clearly state under what condition the accuracy they proposed can be guaranteed. Such ambiguity may induce misunderstanding on the accuracy of the computed sun position and ultimately may make misguided notion on the actual sun tracking system's sun tracking accuracy. This work presents some comments related to the implementation of sun position computational algorithm for the sun tracking system. We first introduce the algorithms proposed in the literature. And then, from sun tracking system user's point of view, we explain the true meaning of accuracy of computed sun position. We also discuss how to select the proper algorithm for the actual implementation. We finally discuss how the input factors used in computation of sun position, like time, position etc, affect the computed sun position accuracy.

• Journal of the Korea Society of Computer and Information
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• v.22 no.1
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• pp.1-7
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• 2017

In this paper, we propose an efficient method that is tracking an object in real time using particle filter and adaptive observation model. When tracking object, it happens object shape variation by camera or object movement in variety environments. The traditional method has an error of tracking from these variation, because it has fixed observation model about the selected object by the user in the initial frame. In order to overcome these problems, we propose a method that updates the observation model by calculating the similarity between the used observation model and the eight-way of edge model from the current position. If the similarity is higher than the threshold value, tracking the object using updated observation model to reset observation model. On the contrary to this, the algorithm which consists of a process is to maintain the used observation model. Finally, this paper demonstrates the performance of the stable tracking through comparison with the traditional method by using a number of experimental data.

• Journal of Broadcast Engineering
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• v.18 no.1
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• pp.1-9
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• 2013

Accuracy of the 3-D model is essential in model-based camera tracking. However, 3-D object modeling requires dedicated and complicated procedures for precise modeling without any errors. Even if a 3-D model contains a certain level of errors, on the other hand, the tracking errors cause by the modeling errors can be different from its perceptual errors; thus, it is an important aspect that the camera tracking can be successful without precise 3-D modeling if the modeling errors are within the user's permissible range. In this paper, we analyze the tolerance of 3-D object modeling errors by comparing computational matching errors with perceptual matching errors through user evaluations, and also discuss permissible ranges of 3-D object modeling errors.

• Journal of Broadcast Engineering
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• v.7 no.1
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• pp.2-9
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• 2002

Recently. VR( Virtual Reality) applications such as virtual studio and virtual character are wifely used In TV programs. and AR( Augmented Reality) applications are also belong taken an interest increasingly. This paper introduces a virtual screen system. which Is a new AR application for broadcasting. The virtual screen system is a real-time video augmentation system by tracking a chroma-patterned moving panel. We haute recently developed a virtual screen system.'K-vision'. Our system enables the user to hold and morse a simple panel on which live video, pictures of 3D graphics images can appear. All the Images seen on the panel change In the correct perspective, according to movements of the camera and the user holding the panel, in real-time. For the purpose of tracking janet. we use some computer vision techniques such as blob analysis and feature tracking. K-vision can work well with any type of camera. requiring no special add-ons. And no need for sensor attachments to the panel. no calibration procedures required. We are using K-vision in some TV programs such as election. documentary and entertainment.