• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.333-338
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• 2019

Satellite communication is not used by many people like mobile communication, but it is a necessary technology for public service and communication services, such as providing the Internet in military, disaster, remote education and medical services, island areas, and infrastructure vulnerable areas. However, most communication modems have problems with two-way communication with server as IP addresses are assigned to floating IP that change every time they communicate with the network. In this paper, we used the Raspberry Pi as the controller of the terminal device to communicate the network through the satellite modem and the PPP protocol, and to solve the problem of the modem with the floating IP, we used the text message function of the satellite modem. Through this process, two-way data links using the Thuraya geostationary orbit satellite were implemented.

• Journal of Advanced Navigation Technology
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• v.24 no.2
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• pp.67-72
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• 2020

Satellite communication is not used by many people like mobile communication, but it is a necessary technology for public service and communication services, such as providing the Internet in military, disaster, remote education and medical services, island areas, and infrastructure vulnerable areas. However, on ships and aircraft, mobile communications requiring base stations are either unavailable or restricted in their use. In this paper, we used a Raspberry Pi board as the terminal device to communicate network through satellite modem and PPP protocol, and implemented two-way data link using the text message of the modem to connect to the Thuraya geo-stationary orbit network. In addition, I/O devices were connected to the controller of the terminal equipment to design and implement an IoT device system for ships that can remotely access the system under control and control I/Os and transmit measured data through various sensors.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.833-836
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• 1999

In this paper, the communication performance and its characteristics of the polar Low Earth Orbit(LEO) mobile satellite have been described in terms of the generalized performance parameters via geometric modeling and analysis. Especially, the general formula related to the parameters such as the number of orbits(M) and the number of satellites per orbit(N) were derived in the LEO satellite system for voice service, and then we applied the general result to IRIDIUM system(M＝6, N＝11) that would be scheduled to commercialize soon. The offered traffic of Inter Satellite Link(ISL), ISL link blocking probability as well as both new call blocking probability and the probability of forced termination for the on going call are calculated as the result of performance analysis.

• Korean Journal of Remote Sensing
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• v.27 no.2
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• pp.203-211
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• 2011

Recently, information communication technologies such as smartphone or mobile app greatly affect various application fields including geo-spatial domain. And development scheme of mobile web app or hybrid app regards as the most important computing technology which is combined each advantage of mobile app and mobile web. Despite these trends, it is general case that satellite images are used for the background image for other contents services. With this motivation, hybrid app for geo-metadata as the base for dissemination and service is designed and implemented as the prototype, in this study. At the design stage, HTML5, which is the core technology on an international standardization process for hybrid app, is applied. In the implementation, PhoneGap and Sencha Touch as mobile SDK(Software Development Kit) supporting HTML5 on cross-platform in open sources are used. In prototype, some KOMPSAT-2 images covering small area and mandatory elements in geo-metafata standard are tested. As mobile industry applications and business service models based on satellite images on mobile platform are progressing and diversifying, it is expected that this approach and implemented prototype are considered as an important reference.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.744-753
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• 2015

This paper presents the results of research on developing marine unified communications to provide VoIP service based on marine satellites. With the recent popularity of smart-phones and other mobile devices, the demand for Internet-based wired and wireless unified technology has been growing in marine environments, and increasing interest is being directed to VoIP products and service models with high price competitiveness and the ability to deliver a variety of services. In this regard, this research designed three instruments, developed their unit modules, and verified their performances. These three instruments included the following: (1) a marine VoIP module equipped with an analogue gateway that can be linked to the existing devices used in vessels, which is more than 80% smaller than that of a land system; (2) a text/voice/video engine for marine satellite communications that runs on technology that minimizes communication data usage, which is a core technology for a marine VoIP service; and (3) a unified communication service that can support multilateral cloud-based message conversations, telephone number-based call functions, and voice/video calling between a private space in a ship and shore.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.135-141
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• 2013

Subway in Korea, most of a metropolitan public transport use only worth ten million people a day floating population of wireless communication can be considered HOT SOPT. These three operators' 2G/3G/4G / Wi-Fi / T-DMB frequency and the number of services to co-exist, and the subway train passengers and subway party for operation and management of the communication network is also the co-subway passenger safety and for this service for the effects of mutual interference of whether the verification was necessary. This research and testing different frequency / communication interference between services and testing to determine whether, through the subway authorities and mobile operators in each frequency-specific interaction check and there is no interference to the safety and quality of subway passengers communication services that can be verified as the data was found. The verification methods in the metro area, not just from one region to determine whether the interference with a common verification methods can be applied.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1057-1066
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• 2023

Global Navigation Satellite System (GNSS) is one of the core technologies for the 4th Industrial Revolution, and its importance is increasingly highlighted in the next generation communications and smart mobility requiring the accurate location information. As the development of the high-performance/high-precesion GNSS technology makes it possible to obtain the more accurate locations information, the location based products and systems, which provide the high-quality service, are being researched/developed. In this paper, we present the results of a survey on the recent research trends and examples, utilizing GNSS technology in fields of the next generation communications and smart mobility, and analyzes the results.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.250-253
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• 2014

Due to limited resource, marine communication is severely limited when compared to communications in land. Radio relay facilities, etc. based on a wired network through a long distance communication is possible. In addition, the aircraft is in the air, the ground-based network service based on long-range straight-line distance and elevation (LOS: Line of Sight) communications. On the other hand, the distance in a straight line to the sea, the sea level because communication is limited or through satellite, underwater communications relay equipment installed in the communication scheme has been investigated.. In this paper, using TCP-based real-time joint maritime security communication links were studied. Harsh marine environment, real-time communication that can provide secure communications and propose a LINK joint. In this study, more secure, and convenient communications at sea, a plan was presented to you.

• Journal of Satellite, Information and Communications
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• v.9 no.2
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• pp.91-95
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• 2014

We could use a social networking service such as data communication, personalized service through smart devices as Tablet computers and smart phones. Because of these characteristics, suitable lectures are provided to mobile device. especially, in Korea Cyber University already had built a lot of infrastructures. But, many mobile devices are used in a small display environment. it could effect on reduce Students' efficiency from taking courses. Therefore, we need effectively in a small display content layout for overcome these problems. In this paper, proposed the platform for Improve learning effect in smartphone education. It studied based on golden section and golden spiral theory. and also, we developed layout for content development using vector method illustration program.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.853-871
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• 2012

The location based service is divided into GPS that uses the artificial satellite or base transceiver station in order to cover the wide area and RTLS(Real Time Location System) using the Zigbee, RFID, CSS(Chirp Spread Spectrum), UWB, Bluetooth and Wi-Fi equipment in the space(close range) limited like the building inside or park. Moreover it also repeats the technical development upon through the acceleration of the development of the wire and wireless infrastructure and determination technology, the development of the Internet, diversification of the contents, and etc. As a result, it is expected to develop around the determination technology, witch is common core technology element, contents technology, Internet and mobile communication technology, and etc. afterward. In this research, the direction we investigate was to find and analyze new technology and standardization trend of LBS in order to contribute to the related industry.