• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.4
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• pp.39-44
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• 2012

This paper propose a transmission method for "Transportation system" that can decide precise position under wide area road traffic environment. For precise position detecting, central station collect multiple receiver station's satellite navigation data and generate correction information. In this process, we need efficient real time transmission method for satellite navigation message that has variable data size. We propose real time data transmission method. This real time transmission method offer efficient processing structure for multiple receiver station's satellite navigation message. This paper explains proposed real time transmission method and proofs this transmission method.

• 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.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.2
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• pp.201-209
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• 2023

Time comparison techniques are required for generating and keeping Coordinated Universal Time (UTC) and to distribute standard clocks. These techniques play an important role in various fields, including science, finance, military, and communication. Among these techniques, Two-Way Satellite Time and Frequency Transfer (TWSTFT) ensures a relatively high accuracy, with a time comparison accuracy at a nanosecond level. However, TWSTFT systems have some limitations, such as the dependency on extra network links. In this paper, we propose an improved method for TWSTFT system operation and design a message structure for the suggestion. Additionally, we estimate the data rate and redundancy for the new TWSTFT signal with the designed message structure.

• International journal of advanced smart convergence
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• v.10 no.2
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• pp.64-72
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• 2021

XML message brokers have a lot of importance because XML has become a practical standard for data exchange in many applications. Message brokers covered in this document store many users. This paper is a study of the processing of twig pattern queries in XML documents using branching node streams in XML message broker structures. This work is about query processing in XML documents, especially for query processing with XML twig patterns in the XML message broker structure and proposed a method to reduce query processing time when parsing documents with XML twig patterns by processing information. In this paper, the twig pattern query processing method of documents using the branching node stream removes the twigging value of the branch node that does not include the labeling value of the branch node stream when it receives a twig query from the client. In this paper, the leaf node discovery time can be reduced by reducing the navigation time of nodes in XML documents that are matched to leaf nodes in twig queries for client twig queries. Overall, the overall processing time to respond to queries is reduced, allowing for rapid question-answer processing.

• Journal of Navigation and Port Research
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• v.46 no.6
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• pp.525-529
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• 2022

In the eLoran system, the Loran Data Channel (LDC) is used to provide precise timing and positioning. The LDC message can be modulated with the Eurofix method, which modulates the transmission time of the 3rd-8th pulse not used for navigation, and the 9th pulse method, which modulates data using the 9th additional pulse after the existing 8 Loran pulses. In this paper, we analyzed the reception performance of the LDC message transmitted from the eLoran transmitter according to the modulation method. The eLoran testbed transmitter in Incheon was set to transmit LDC messages simultaneously with the 9th pulse modulation method and the Eurofix modulation method. Then, the LDC messages stored in the databases of the eLoran differential stations in Incheon and Pyeongtaek were analyzed in terms of the message reception rate according to the modulation method. Using the navigation aid management ship Inseong No. 1, the range of LDC message reception of actual sea users near Incheon Port was also analyzed. The results of this study are expected to be utilized in the full operational capability service after the eLoran pilot service.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.3
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• pp.173-179
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• 2022

The satellite navigation deception technology disturbs the navigation solution of the receiver by generating a deceptive signal simulating the actual satellite for the satellite navigation receiver mounted on the unmanned aerial vehicle, which is the target of deception. A single spoofing technique that creates a single deceptive position and velocity can be divided into a synchronized spoofing signal that matches the code delay, Doppler frequency, and navigation message with the real satellite and an unsynchronized spoofing signal that does not match. In order to generate a signal synchronized with a satellite signal, a very sophisticated and high precision signal generation technology is required. In addition, the current position and speed of the UAV equipped with the receiver must be accurately detected in real time. Considering the detection accuracy of the current radar technology that detects small UAVs, it is difficult to detect UAVs with an accuracy of less than one chip. In this paper, we assume the asynchrony of a single spoofing signal and propose a region defense technique using multiple spoofing signals.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.100-101
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• 2012

According to growing the leisure boat market, safety-related and weather information have been required by different users with different electronic devices. NAVTEX messages transmitting worldwide from local stations are a kind of useful service, even for non mandatory carriage requirement vessel, such as small or fishing vessels. However, it is not easy for all users to recognize intuitively. This paper is to implement the NAVTEX message on tablet PC, indicating warning positions of message on Android-based google map.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.4
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• pp.51-56
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• 2011

In this paper, we propose a CAN message compression method using bit rearrangement to reduce the CAN bus load and the error probability during the transmission of CAN messages. In conventional CAN message compression methods, message compression is accomplished by sending only the differences between the previous data and the current data. In the proposed method, the difference bits are rearranged to further increase the compression efficiency. By simulations in car applications, it is shown that the CAN transmission data is further reduced up to 26% by the proposed method, compared with the conventional method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.194-196
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• 2010

'09. 12. 4 인천항 갑문 앞 충돌사건 이후 유사사고 발생 재발 방지를 위하여 여러 가지 대책을 수립하여 시행해오고 있다. 그 중에서도 관제사의 동시다발적 관제에 따른 관제공백 발생 최소화를 위한 방안 모색이 중심과제라 할 것이다. 현장 실사를 통해서 인천항 이용 선박의 항해통신 장비 현황과 항행정보 요구 수준을 먼저 알아보았다. 본 연구에서는 AIS의 TEXT MESSAGE를 기반으로 한 자동정보시스템을 이용하여 VTS가 선박운항자에게 적시적소에 항만운영정보 및 항행안전정보를 제공하는 방안을 검토하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.91-93
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• 2011

현재 VTS센터에서 사용되고 있는 항만자동안내방송시스템은 VHF음성통신을 기반으로 하고 있어 그 방송범위에 제약이 있다. 최근 AIS의 보급이 확대됨에 따라 AIS신호가 연안해역에서 약 100마일까지 송수신이 되고 있다. 이에 본 연구에서는 기존에 전국의 VTS에 설치되어 있는 VHF음성통신 항만자동안내방송시스템에 AIS TEXT MESSAGE기능을 통합 운영하여 연안해역까지 해상안전을 위한 자동안내방송을 확대하고자 함이 그 목적이다.