• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.3 s.357
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• pp.85-91
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• 2007

Satellite Digital Multimedia Broadcasting (S-DMB) is the digital convergence service of broadcasting and communication for mobility and portability. Broadcasting service of S-DMB can be taken by the mobile phone or vehicle terminals anytime and anywhere. S-DMB system is currently providing 11 video channels and 26 audio channels. As the demand of multimedia service is recently increasing, S-DMB system needs high quality and new contents service. Therefore we need to make efficient S-DMB with more channel ability and high transmission quality. In this paper, we propose new S-DMB system that can be applied to powerful channel coding scheme and hierarchical 8-PSK(8-Phase Shift Keying) modulation with Backwards Compatibility modes that simultaneously can support both current and new system. And we analyze the performance of current S-DMB system and verify a possibility of advanced S-DMB through computer simulation.

• Korean Journal of Remote Sensing
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• v.30 no.4
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• pp.445-454
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• 2014

In recent days, trend technologies for cloud, bigdata, or mobile, as the important marketable keywords or paradigm in Information Communication Technology (ICT), are widely used and interrelated each other in the various types of platforms and web-based services. Especially, the combination of cloud and mobile is recognized as one of a profitable business models, holding benefits of their own. Despite these challenging aspects, there are a few application cases of this model dealing with geo-based data sets or imageries. Among many considering points for geo-based cloud application on mobile, this study focused on a performance test of mobile cloud of Bayesian image fusion algorithm with satellite images. Two kinds of cloud platform of Amazon and OpenStack were built for performance test by CPU time stamp. In fact, the scheme for performance test of mobile cloud is not established yet, so experiment conditions applied in this study are to check time stamp. As the result, it is revealed that performance in two platforms is almost same level. It is implied that open source mobile cloud services based on OpenStack are enough to apply further applications dealing with geo-based data sets.

• Journal of Multimedia Information System
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• v.7 no.2
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• pp.147-156
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• 2020

The author Nakajima was involved in the field of disaster communications and emergency medical care as guest research scientist at the Fukushima Nuclear Accident Independent Investigation Commission established by the National Diet of Japan and reviewer of the Commission's report, and Kurokawa was the chairman of this Commission. Looking back over a decade, we are on the liability issue of bureaucrats and telecom operators, so it's becoming clear what was hidden at the time. The battery of NTT DoCoMo's mobile phone repeaters had a capacity of only about 24 hours, and communication failures increased after one day. The Government also failed to issue an announcement of "Vent from reactor" under the Telecommunications Act Article No. 129. This mistake lost the opportunity to use the third-party telecommunications (e.g. taxi radios). Furthermore, as a result of LASCOM (telecommunications satellite network for local governments via GEO) and a variety of unexpected communication failures, the evacuation order "Escape!" could not be notified to the general public well. As a result, the general public was exposed to unnecessary radiation exposure. Such bureaucratic slow action in emergencies is common in the response to the 2020 coronavirus.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.902-905
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• 2008

With development of internet, location-based service (LBS) is getting more interest in wire and wireless network, and many studies are in progress to provide various services such as GIS and GPS technique related to this. Today positioning and information providing service is accomplished by mobile communication companies' chasing the cell or building unique GIS system, but there is a lot of building-cost that must be endured to define boundary of collecting precise location information from chasing Cell and provide unique location information service. In this paper, it desires to make the database of location information with using GPS, relatively precise satellite positioning system, to cut the cost of building location information service, and to present service models such as children's positioning service that is to reduce the cost of building GIS by using Web Open API and provide location information of discrete object in real-time.

• Journal of the Korea Safety Management & Science
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• v.13 no.1
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• pp.107-114
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• 2011

Location-Based Service(LBS) is a service that provides a variety of convenience in life using location information that can be obtained by mobile communication network or satellite signal. In order to provide LBS precisely and efficiently, we need the location determination technology, platform technology and server technology. In this study, we studied on how we can reduce the error on location determination of objects such people and things. Fingerprint location determination method was applied to this study because it can be used at current wireless communication infrastructure and less influenced by a variety of noisy environment than other location determination methods. We converted the probability value to logarithmic scale value because using the sum of k probability values is not suitable to be applied to weight determination. In order to confirm the performance of suggested method, we developed location determination test program with Visual Basic 6.0 and performed the test. According to indoor and outdoor test results, the suggested stochastic method reduced the distance error by 17%, 18% and 9% respectively at indoor environment and 25%, 11% and 4% at outdoor environment compared with deterministic NN, kNN and kWNN fingerprint methods.

• Journal of the Korea Safety Management & Science
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• v.13 no.1
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• pp.99-105
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• 2011

Location-Based Service(LBS) is a service that provides a variety of convenience in life using location information that can be obtained by mobile communication network or satellite signal. In order to provide LBS precisely and efficiently, we have to need technologies such as location determination technology, platform technology and server technology first. In this study, we studied on how we can reduce the error on location determination of objects such people and things. Fingerprint location determination method was applied to this study because it can be used at current wireless communication infrastructure and less influenced by a variety of noisy environment than other location determination methods. We used the time of arrival(ToA) method in fingerprint location determination method. In order to confirm the performance of suggested method, we developed location determination test program with LAbVIEW 2010 and performed the test. According to indoor test results, the suggested method reduced the distance error by 24%, 34% and 19% respectively at indoor environment compared with deterministic kWNN and Rice Gaussian fingerprint methods.

• Korean Security Journal
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• no.13
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• pp.145-168
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• 2007

Like to change to the information-oriented society, the guard service needs to be changed. The communication and hardware technology develop rapidly and according to the internet environment change from cable to wireless, modern person can approach every kinds of information service using wireless communication machinery which can be moved such as laptop, computer, PDA, mobile phone and so on, LBS field which presents the needing information and service at anytime, anywhere, and which kinds of device expands it's territory all the more together with the appearance of ubiquitous concept. LBS use the chip in the mobile phone and make to confirm the position of the joining member anytime within several tens centimeters to hundreds meters. LBS can be divided by the service method which use mobile communication base station and apply satellite. Also each service type can be divided by location chase service, public safe service, location based information service and so on, and it is the part which will plan with guard service development. It will be prospected 8.460 hundred million in 2005 years and 16.561 hundred million in 2007 years scale of market. Like this situation, it can be guessed that the guard service has to change rapidly according to the LBS application. Study method chooses documentary review basically, and at first theory method mainly uses the second documentary examination which depends on learned journal and independent volume which published in the inside and the outside of the country, internet searching, other kinds of all study report, statute book, thesis which published at public order research institute of the Regional Police Headquarter, police operation data, data which related with statute, documents and statistical data which depend on private guard company and so on. So the purpose of the study gropes in accordance with the LBS application, and present the problems and improvement method to analyze indirect of manager side of operate guard adaptation service of LBS, government side which has to activate LBS, systematical, operation management, manpower management and education training which related with guard course side which has to study and educate in accordance with application of the new guard service, as well as intents to excellent quality service of guard.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.1
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• pp.23-39
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• 2005

As developing satellite communication, the tracking range of the moving objects which move in local area is expanded to the whole world. However previous logistics management system is able to monitor freight which transporting in local area using mobile communication system. In this paper, we propose the reefer container management system that manages the location information and other related information such as temperature, humidity of container using the satellite system. The proposed system consists of three parts; data collector, satellite communication manager, reefer container information manager. And the proposed system uses the moving object index for managing the trajectory of container and tracing the location of container or vessel that is transporting the container, and supports various services such as reefer container and vessel tracking, container control and container statistics to logistic companies like shipper and forwarding agent. And the system can be increasing the quality of container transportation service to the shipper, and it makes the efficient management of reefer container to the shipping company.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.12
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• pp.51-60
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• 2004

DAB(Digital Audio Broadcasting) is a new media service that can provide CD quality audio, various data service, interactive and high quality mobile communications through popular media such as terrestrial broadcasting, satellite, cable TV, and internet. In this paper, a new EPG(Electronic Program Guide) application model is proposed. The model is based on DAB and combines a DAB receiver and PCs so that it can take advantages of using various multimedia services and plenty of internet contents. The developed EPSD(EPG Provider System on DAB) has Web-based Server/Client structure and povides EPG functionalities to client PCs over internet. Therefore, the DAB receiver can be smaller and cheaper, and can develop abundant data services on internet. It can also provide high quality video services and be expected to become an important component in future home network systems.

• Electronics and Telecommunications Trends
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• v.33 no.3
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• pp.1-10
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• 2018

This article presents spectrum sharing policy trends both overseas and domestically. The Federal Communications Commission recently adopted rules for the commercial use of a 150 MHz bandwidth at 3.55 to 3.7 GHz, which has been utilized for defense and satellite services. This frequency band for spectrum sharing is called the citizens broadband radio service (CBRS) band. In Europe, the related regimes for licensed shared access application at 2.3 to 2.4 GHz has been organized, and interface standardization for sharing frequency information has been completed. In Korea, efforts are being made to establish spectrum-sharing policies to improve the efficiency of the frequency utilization. This article also introduces both the IEEE 802 local area network/metropolitan area network and 3GPP standardization activities with regard to frequency sharing technologies. To effectively solve the spectrum-sharing problem in IEEE 802, standardization activities on the CBRS and the mid-band (3.7-24 GHz) are underway. 3GPP is currently developing the standardization of a licensed assisted access technology, which extends mobile communication services provided in the licensed band to unlicensed bands.