• Journal of the Korean Society for information Management
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• v.23 no.2
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• pp.147-165
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• 2006

The explosive growth of Web-based educational resources requires a new approach for accessing relevant information effectively. Social searching in the context of social navigation is one of several answers to this problem, in the domain of information retrieval. It provides users with not merely a traditional ranked list, but also with visual hints which can guide users to information provided by their colleagues. A personalized and context-dependent social searching system has been implemented on a platform called KnowledgeSea II, an open-corpus Web-based educational support system with multiple access methods. Validity tests were run on a variety of aspects and results have shown that this is an effective way to help users access relevant, essential information.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4797-4813
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• 2018

The transform domain communication system (Hereinafter referred to as TDCS) takes on numerous advantages, inclusive of anti-jamming and low probability of detection. Yet its application is confined by the consistent spectrum in the transmitter and receiver, which is not possible in the case of a huge distance exsits between them. In this paper, a TDCS based modified weighted fractional fourier transform (WFRFT) is proposed to solve the problem resulting from spectrum mismatching for TDCS application. The amplitude and phase information are incorporated with the TDCS signals and transmit to the receiver together in the wake of a modified WFRFT. The basic function and the TDCS signals shall be accessible to the receivers in the wake of an inverse WFRFT transform, which make sure that the original information can be demodulated properly. The system's reliability while transmitting signals with different modulation methods and with spectrum mismatching is demonstrated by bit error rate (BER). In the meantime, the constellations of the signals and the BER performances at the eavesdropper demonstrate the proposed system is better secured.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.2
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• pp.73-90
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• 2018

Various navigation systems are integrated with the Global Navigation Satellite System (GNSS) to improve navigation performance so that continuous navigation information can be obtained even when navigation performance is degraded or navigation is not available due to the outage of GNSS. Time and cost can be reduced by evaluating performance of the integrated navigation system through Modeling and Simulation (M&S) software prior to the deployment of the integrated navigation system. The measurements of the navigation system should be generated to evaluate performance through of the navigation system M&S software. This paper proposes a method of designing a navigation environment generation module in M&S software of the integrated navigation system. To show applicability of the proposed method to M&S software design of the integrated navigation system, functions are verified through MATLAB. And then visual C++ based M&S software for the integrated navigation system is implemented to check the operation of the navigation environment generation module. The reference trajectory is generated and true measurements of Global Positioning System (GPS), Korea Positioning System (KPS), and enhanced Long range navigation (eLoran) are generated from the reference trajectory. The navigation results obtained from the true measurements are compared with the reference trajectories. The results show that the measurements generated using the design generation module by the proposed method are valid and the navigation environment generation module can be applied to M&S software of the integrated navigation system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.308-309
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• 2022

The Ministry of Oceans and Fisheries is providing maritime safety services using combine limited artificial intelligence technologies through the operation of the Korean e-Navigation service, and research is needed to improve reliability and quality to secure the competitiveness of the system. However, linking real-time operating systems requires a separate system configuration that can be linked after processing personal information security with minimal performance impact. To solve this problem, this study will make a basic design of a big-data maritime information gateway system of the Korean e-Navigation service that minimizes the impact of performance and reflects the security of personal information.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2424-2430
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• 2012

The current Navigation System for the Visually Impaired Person has a short and limited communication distance and can't receive enough information from Visually Impaired Person to assist directly. In addition, because the path is dangerous and incomplete for the Visually Impaired Person, moving with White Stick is still inconvenient and dangerous. To solve this problem we implement communication that can send and receive video, voice, location information between the Visually Impaired Person's Smart Portable Navigation System Development and assistant's PC.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.3
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• pp.189-196
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• 2021

In this paper, we propose techniques to correct the altitude error and heading error of 3D Pedestrian Inertial Navigation (PIN). When a PIN is used to estimate the location of a pedestrian only with an Inetrial Measurement Unit (IMU) without infrastructure, there is a problem in that the location error gradually increases due to the limitation of the observability of the filter. To solve this problem without additional sensors, we propose two techniques in this paper. First, stair walking is recognized in consideration of the altitude difference that may occur during one step. If it is recognized as stair walking, only Zero-velocity UPdaTe (ZUPT) is performed, and if it is recognized as level walking, ZUPT + Altitude Damping (AD) is performed together to correct the altitude error. Second, the straight-line movement direction is calculated through the difference of the estimated position, and the heading error is corrected by matching this information with the link information of the digital map. By applying these techniques, it is verified through real tests that accurate three-dimensional location information of pedestrians can be estimated without infrastructure.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.1
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• pp.35-42
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• 2021

In this paper, we identified the national alert service and recognized the problem that disaster message is received only from smart phones, which are mobile communication devices in the event of a disaster. Thus, we conducted a study on how to use NFC to identify disaster characters in navigation. Research was conducted on how to receive and utilize disaster message and disaster information when using smart phone navigation as well as application development-enabled navigation. If studies such as those in question continue, disaster situations and information will be provided in a more diverse environment and users will all be able to access disaster content to prepare for disasters and prevent or reduce damage.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.107-110
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• 2008

In this study, we propose a system for setting a Destination on CNS(Car Navigation System) or PNS(Personal Navigation System). The present Navigation does set the destination by only static method like name search, address search and wire telegraph telephone number search. But, the kind of setting a static destination does not reflect the dynamic moving situation. So we suggest setting the destination of navigation using Identifier of moving terminal. And it includes privacy protection on personal position information

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.1
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• pp.109-115
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• 2016

Nowadays, smart devices are the target of the digital forensic investigation. Among various smart devices, we can obtain much information from smart phone which is provided with continuous power and used for data communication. This paper deals with the traces to be left in Android smart phones after using the navigation applications with the GPS function. We selected navigation applications(domestic and overseas) which have a high number of download times, anaylzed them and discussed the meaning of the analysis result in digital forensic investigation.

• Spatial Information Research
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• v.15 no.4
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• pp.363-370
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• 2007

This study has been carried for the development of the basic algorithm of helicopter navigation system based on TRN (Terrain Referenced Navigation) with information input from the GPS. The helicopter determines flight path due to Origination-Destination analysis on the Cartesian coordinate system of 3-D DTM. This system shows 3-D mesh map and the O-D flight path profile for the pilot's acknowledgement of the terrain, at first. The system builds TCF (terrain clearance floor) far the buffer zone upon the surface of ground relief to avid the ground collision. If the helicopter enters to the buffer zone during navigation, the real-time warning message which commands to raise the body pops up using Matlab menu. While departing or landing, control of the height of the body is possible. At present, the information (x, y, z coordinates) from the GPS is assumed to be input into the system every 92.8 m of horizontal distance while navigating along flight path. DTM of 3" interval has been adopted from that which was provided by ChumSungDae Co., Ltd..