• Journal of Korea Multimedia Society
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• v.23 no.10
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• pp.1258-1269
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• 2020

The IoT(Internet of Things) service provides users with valuable services by collecting and analyzing data using Internet-connected IoT devices. Currently, IoT service platforms are accomplished by using edge computing to reduce the delay time required to collect data from IoT devices. However, if a user moves to another network with IoT device, the connection will be lost and IoT service will be suspended. To solve this problem, we proposes a service that automatically roaming IoT service when IoT device makes move. IoT roaming service provides a device automatic tracking management technique designed to continue receiving IoT services even if users move to other networks. To check if the proposed roaming service was effective, we implemented IoT roaming service and measured the data transfer time while move between networks along with devices while using IoT service. As a result, the average data transfer time was 124.62ms, and the average service interrupt time was 812.12ms. with this result, we can assume that the user could feel service interruption time very shortly and it will not affect the service experience. with IoT roaming service, we expect that it will present a method that stably providing IoT services even if user moves networks.

• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.1-8
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• 2016

Current indoor intrusion detection and location tracking methods have the weakness in seamless operations in tracking the objective because the object must possess a communicating device and the limitation of the single cell size (approximate $100cm{\times}100cm$) exits. Also, the utilization of CCTV technologies show the shortcomings in tracking when the object disappear the area where the CCTV is not installed or illumination is not enough for capturing the scene (e.g. where the context-awarded system is not installed or low illumination presents). Therefore, in this paper we present an improved in-door tracking system based on sensor networks. Such system is built on a simulated scenario and enables us to detect and extend the area of surveillance as well as actively responding the emergency situation. Through simulated studies, we have demonstrated that the proposed system is capable of supplementing the shortcomings of signal cutting, and of estimating the location of the moving object. We expect the study will improve the better analysis of the intruder behavior, the more effective prevention and flexible response to various emergency situations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11A
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• pp.1066-1072
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• 2010

In this paper we proposed a multi event handling surveillance system using multiple PTZ cameras. One event is assigned to each PTZ camera to detect unusual situation. If a new object appears in the scene while a camera is tracking the old one, it can not handle two objects simultaneously. In the second case that the object moves out of the scene during the tracking, the camera loses the object. In the proposed method, the nearby camera takes the role to trace the new one or detect the lost one in each case. The nearby camera can get the new object location information from old camera and set the seamless event link for the object. Our simulation result shows the continuous camera-to-camera object tracking performance.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2780-2782
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• 2005

In this paper, we present a mobile robot localization solution by using a Ubiquitous Vision System (UVS). The collective information gathered by multiple cameras that are strategically placed has many advantages. For example, aggregation of information from multiple viewpoints reduces the uncertainty about the robots' positions. We construct UVS as a multi-agent system by regarding each vision sensor as one vision agent (VA). Each VA performs target segmentation by color and motion information as well as visual tracking for multiple objects. Our modified identified contractnet (ICN) protocol is used for communication between VAs to coordinate multitask. This protocol raises scalability and modularity of thesystem because of independent number of VAs and needless calibration. Furthermore, the handover between VAs by using ICN is seamless. Experimental results show the robustness of the solution with respect to a widespread area. The performance in indoor environments shows the feasibility of the proposed solution in real-time.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.6
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• pp.121-130
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• 2009

In this paper, Gaussian probability distribution model based multi-sensor data fusion algorithm is proposed for a vehicular location awareness system. Conventional vehicular location awareness systems are operated by GPS (Global Positioning System). However, the conventional system is not working in the indoor of building or urban area where the receiver is difficult to receive the signal from satellites. A method which is combined GPS and UWB (Ultra Wide-Band) has developed to improve this problem. However, vehicular is difficult to receive seamless location information since the measurement systems by both GPS and UWB convert the vehicle's movement information separately at each sensor. In this paper, normalized probability distribution model based Hybrid UWB/GPS is proposed by utilizing GPS location data and UWB sensor data. Therefore the proposed system provides information with seamless and location flexible properties. The proposed system tested by Ubisense and Asen GPS in the $12m{\times}8m$ outdoor environments. As a result, the proposed system has improved performance for accurateness and connection ability between devices to support various CNS (Car Navigation System).

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.1-9
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• 2021

The hologram pyramid is an application of floating holograms, allowing the observer to see three-dimensional holograms from various angles without wearing wearable devices. Due to the low cost and ease of manufacturing, it has been used in a wide variety of fields as diverse as education, prototyping, showcase, and etc. But, when the observer looks at the hologram from the place where each side of the hologram pyramid is connected, the hologram looks cut and distorted. Also, the observer can see the only hologram of angles viewed head-on from each side. In this paper, we propose a method of generating a hologram image corresponding to the observer's gaze angle by tracking the observer's position and conducting reverse distortion. It provide a hologram of the angle viewed by the observer without cutting and distortion. In addition, the existing method and the proposed method were applied and compared in the hologram pyramid.

• Korean Journal of Construction Engineering and Management
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• v.18 no.2
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• pp.21-29
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• 2017

Recently, with having a great interest of the general public for the AR (Augmented Reality) technology, there have been lots of study to improve efficiency of a construction equipment with applying the AR technology to a construction equipment. The clear extrinsic calibration is essential to applying AR technology at the construction site without any error which came from superimposition between 'Real world' and 'Virtual world'. However, on the construction site, the clear extrinsic calibration is not possible, because of lack of time and budget for the specific survey, also, the huge error of the outdoor tracking system such as gyro, GPS system and so on. In this study, we do research about seamless superposition with unclear extrinsic calibration and the image process method for making AR navigator operating in the excavator. Based on this study, we figure that we can fully develop the AR navigator for the excavator. Furthermore, thereby operating AR navigator at many construction sites, we expect that the efficiency of the excavator will be improved. In addition, we can develop AR navigator for not only a excavator but all about construction equipment.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.251-264
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• 2008

One of the crucial elements to fully facilitate the various benefits of intelligent transportation systems (ITS) is to obtain more reliable traffic monitoring in real time. To date, point and section-based traffic measurements have been available through existing surveillance technologies, such as loops and automatic vehicle identification (AVI) systems. However, seamless and more reliable traffic data are required for more effective traffic information provision and operations. Technology advancements including vehicle tracking and wireless communication enable the acceleration of the availability of individual vehicle travel information. This study presents a UBIquitous PRObe vehicle Surveillance System (UBIPROSS) using vehicle-to-vehicle (V2V) wireless communications. Seamless vehicle travel information, including origin-destination information, speed, travel times, and other data, can be obtained by the proposed UBIPROSS. A set of parameters associated with functional requirements of the UBIPROSS, which include the market penetration rate (MPR) of equipped vehicles, V2V communication range, and travel time update interval, are investigated by a Monte Carlo simulation- (MCS) based evaluation framework. In addition, this paper describes prototypical implementation. Field test results and identified technical issues are also discussed. It is expected that the proposed system would be an invaluable precursor to develop a next-generation traffic surveillance system.

• Journal of Korea Multimedia Society
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• v.9 no.4
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• pp.421-433
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• 2006

This paper proposes a method to insert virtual objects into a real video stream based on feature tracking and camera pose estimation from a set of single-camera video frames. To insert or modify 3D shapes to target video frames, the transformation from the 3D objects to the projection of the objects onto the video frames should be revealed. It is shown that, without a camera calibration process, the 3D reconstruction is possible using multiple images from a single camera under the fixed internal camera parameters. The proposed approach is based on the simplification of the camera matrix of intrinsic parameters and the use of projective geometry. The method is particularly useful for augmented reality applications to insert or modify models to a real video stream. The proposed method is based on a linear parameter estimation approach for the auto-calibration step and it enhances the stability and reduces the execution time. Several experimental results are presented on real-world video streams, demonstrating the usefulness of our method for the augmented reality applications.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12C
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• pp.727-737
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• 2011

This paper presents an implementation scheme of real-time lane and vehicle detection system with FPGA and DSP. In this type of implementation, defining the functionality of each device in efficient manner is of crucial importance. The FPGA is in charge of extracting features from input image sequences in reduced form, and the features are provided to the DSP so that tracking lanes and vehicles are performed based on them. In addition, a way of seamless interconnection between those devices is presented. The experimental results show that the system is able to process at least 15 frames per second for video image sequences with size of $640{\times}480$.