• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6196-6203
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• 2013

This study examined cadastral surveying technology regulated under the "Special Law for the cadastral surveying", and analyzed the related surveying methods currently used. Based on the analysis, this study suggested the efficient application plan future cadastral surveying projects. The new technologies analyzed were GNSS, GPS RTK, Network RTK, GPS Augmentation System, and the mobile and auto sighting TS. As a result of the analysis, this study suggests that if a receiving technology is possible for the integrated receiving of GPS/GLONASS/Galileo systems, both the accuracy of location determination could be enhanced and stable data could be obtained. The Network RTK technology may solve the constraint receiving factors of satellite information in the long term if a GPS Augmentation System is used. Finally, mobile and auto sighting TS technologies can reduce the personnel factors, but can be applied after the offset problem is overcome.

• Journal of Computing Science and Engineering
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• v.5 no.3
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• pp.210-222
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• 2011

In this work, we study the problem of privacy-preservation data publishing in moving objects databases. In particular, the trajectory of a mobile user in a plane is no longer a polyline in a two-dimensional space, instead it is a two-dimensional surface of fixed width $2A_{min}$, where $A_{min}$ defines the semi-diameter of the minimum spatial circular extent that must replace the real location of the mobile user on the XY-plane, in the anonymized (kNN) request. The desired anonymity is not achieved and the entire system becomes vulnerable to attackers, since a malicious attacker can observe that during the time, many of the neighbors' ids change, except for a small number of users. Thus, we reinforce the privacy model by clustering the mobile users according to their motion patterns in (u, ${\theta}$) plane, where u and ${\theta}$ define the velocity measure and the motion direction (angle) respectively. In this case, the anonymized (kNN) request looks up neighbors, who belong to the same cluster with the mobile requester in (u, ${\theta}$) space: Thus, we know that the trajectory of the k-anonymous mobile user is within this surface, but we do not know exactly where. We transform the surface's boundary poly-lines to dual points and we focus on the information distortion introduced by this space translation. We develop a set of efficient spatiotemporal access methods and we experimentally measure the impact of information distortion by comparing the performance results of the same spatiotemporal range queries executed on the original database and on the anonymized one.

• Journal of Korea Multimedia Society
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• v.11 no.11
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• pp.1575-1591
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• 2008

In this paper, we propose a new method detecting foot motion capture in order to overlap in realtime foot's 3D virtual model from stereo cameras. In order to overlap foot's virtual model at the same position of the foot, a process of the foot's joint detection to regularly track the foot's joint motion is necessary, and accurate register both foot's virtual model and user's foot in complicated motion is most important problem in this technology. In this paper, we propose a dynamic registration using two types of marker groups. A plane information of the ground handles the relationship between foot's virtual model and user's foot and obtains foot's pose and location. Foot's rotation is predicted by two attached marker groups according to instep of center framework. Consequently, we had implemented our proposed system and estimated the accuracy of the proposed method using various experiments.

• Journal of Advanced Navigation Technology
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• v.13 no.3
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• pp.459-465
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• 2009

Digital watermarking is a technique to insert a visually imperceptible information into an image so that the information can be extracted for the purposes of ownership verification or authentication. And watermarking techniques can be classified as either fragile or robust. Robust watermarks are useful for copyright and ownership assertion purposes. They cannot be easily removed and should resist common image manipulation procedures such as rotation, scaling, cropping, etc. On the other hand, fragile watermarks are easily corrupted by any image processing procedure, it can detect any change to an image as well as localizing the areas that have been changed. In this paper, we propose a fragile watermarking algorithm using a special hierarchical structure for integrity verification of image and detection of manipulated location. In the proposed method, the image to be watermarked is divided into blocks in a multi-level hierarchy and calculating block digital signatures in this hierarchy. The proposed method thwarts the cut-and-paste attack and the experimental results to demonstrate the effectiveness of the proposed method.

• Journal of Korea Multimedia Society
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• v.17 no.3
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• pp.364-372
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• 2014

This research enables the user to have access to the desired service which is on the multi-platform display device by establishment customized Digital Signage System using the SaaS method. This system is significantly favorable due to the following points: the expandibility and portability is outstanding compared with the existing signage system, establishment expenses may be reduced because the platform can be established in various configurations independently, maintenance and management, and the strong point of the system is that costs can be reduced due to the fact that the electric power can be controlled according to environmental situations. Various researches should be conducted simultaneously such as researches on automatic pattern recognition technologies which recognizes the sex, age, location among other data of the user and various methods of image processing for the production of contents to elaborate lively contents to provide diverse experience and enjoyable configurations for the future generation.

• Journal of Advanced Navigation Technology
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• v.21 no.6
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• pp.585-592
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• 2017

Recently, as the air traffic volume has been explosively increased, various studies are being conducted to increase the air passenger capacity. In order to compensate the limitation of the separation distance on the aerodrome established on the basis of existing VOR / DME equipment, GNSS utilizing satellite is considered. In addition, we are trying to obtain more precise location information by using SBAS, a system that can correct GNSS error. ICAO recommends introducing SBAS until 2025, and Korea has also started to develop KASS, a Korean SBAS since 2014. Therefore, in this paper, we analyze the interference threshold for the measurement items and the receiving antenna gain according to the elevation angle of the satellite receiving antenna.

• Journal of information and communication convergence engineering
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• v.18 no.2
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• pp.123-131
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• 2020

After observing that most tourists plan to complete their visits to multiple cultural heritage sites within one day, we surmised that for many museum visitors, the foremost thought is with regard to the amount of time is to be spent at each location and how they can maximize their enjoyment at a site while still balancing their travel itinerary? Recommendation systems in e-commerce are built on knowledge about the users' previous purchasing history; recommendation systems for museums, on the other hand, do not have an equivalent data source available. Recent solutions have incorporated advanced technologies such as algorithms that rely on social filtering, which builds recommendations from the nearest identified similar user. Our paper proposes a different approach, and involves providing dynamic recommendations that deploy social filtering as well as content-based filtering using term frequency-inverse document frequency. The main challenge is to overcome a cold start, whereby no information is available on new users entering the system, and thus there is no strong background information for generating the recommendation. In these cases, our solution deploys statistical methods to create a recommendation, which can then be used to gather data for future iterations. We are currently running a pilot test at Chao Samphraya national museum and have received positive feedback to date on the implementation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3B
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• pp.72-84
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• 2005

Optical burst switching networks usually employ one-way reservation by sending a burst control packet with a specific offset time, before transmitting each data burst Same. Due to such a Property, burst-contentions occur when multiple bursts contend for the same wavelength in the same output link simultaneously in a node, leading to burst losses, eventually degrading the quality of service. Therefore, in this paper, we propose a dynamic routing algorithm using minimum local state information in order to decrease burst-contentions. In this proposed scheme, if burst loss rate exceeds a threshold value at a certain node, a new alternative routing path is chosen according to burst priority and location of burst generation, which enables the contending bursts to detour around the congested link. Moreover, for reducing the effect of sending bursts on the primary path due to the alternative path, we also apply a minimum path-cost based routing on link-cost concept. Our simulation results show that proposed scheme improves the network performance in terms of burst loss probability and throughput by comparing with conventional one.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.6
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• pp.1058-1069
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• 2015

In wireless sensor networks, geographic routing is known as an efficient method to transmit the data packet using the location information. Geographic routing relies on two techniques: greedy forwarding and face routing. Face routing helps to recover from greedy routing fail and is based on the planar graph in which does not cross each edge. However, the planarization causes frequently short transmission of data packet because it removes other edges except the shortest one. In other words, since the planarization removes the long edges, face routing could not exploit the efficient removed edges of communication graph. This problem brings about the excessive energy consumption of nodes. In this paper, we propose an energy efficient face routing protocol in wireless sensor networks. This proposed protocol searches the removed edges and transmits them via the edges. Simulation shows that the proposed protocol is more efficient in terms of energy consumption than the previous face routing.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.478-484
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• 2017

This study analyzed statistically the determinants that affect the royalties of knowledge technology transfer, which accounts for a considerable portion of university technology transfer. As knowledge technology transfer certainly includes a move from tacit knowledge from one side to the other side per se, the scope of knowledge technology transfer is unclear and numerical information of technology transfer, such as research fund scale, which is used widely in previous studies, cannot be used in the analysis. Therefore, this study focused on the researcher characteristics and included its explanatory variables in the present study. In addition, it included the technical characteristics of the knowledge transferred and the characteristics of the contracting company. The knowledge maturity calculated from the appointment year and contract date positively affects the technology royalties, but work experience and patent activity of the researcher are not statistically significant. Statistically significant differences in the technology royalty according to the type of technology transfer and the company location were observed, but there was no meaningful change in the technology royalty depending on the technical field and company business scale.