• 한국정보처리학회논문지
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• 제7권4호
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• pp.1175-1183
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• 2000

Base on the development of mobile communication, the future mobile communication systems were expected to provide higher quality of multimedia services for users than today's systems. Therefore, many technical factors are needed in this systems. Especially these secrecy and the safety would be obtained through the introduction of the security for mobile communication. In this paper, we presents weaknesses and propose required properties in mobile communication. Based on those proposed properties, we propose a new 'call set-up' and 'hand-off' protocol for authentication and key distribution. Also we compare between the proposed scheme and conventional schemes.

• ETRI Journal
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• 제41권2호
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• pp.224-234
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• 2019

This paper proposes a new spectrum forecasting (SF) model to estimate the spectrum demands for future mobile broadband (MBB) services. The model requires five main input metrics, that is, the current available spectrum, site number growth, mobile data traffic growth, average network utilization, and spectrum efficiency growth. Using the proposed SF model, the future MBB spectrum demand for Malaysia in 2020 is forecasted based on the input market data of four major mobile telecommunication operators represented by A-D, which account for approximately 95% of the local mobile market share. Statistical data to generate the five input metrics were obtained from prominent agencies, such as the Malaysian Communications and Multimedia Commission, OpenSignal, Analysys Mason, GSMA, and Huawei. Our forecasting results indicate that by 2020, Malaysia would require approximately 307 MHz of additional spectrum to fulfill the enormous increase in mobile broadband data demands.

• Journal of Communications and Networks
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• 제11권1호
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• pp.36-41
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• 2009

The IEEE 802.16 wireless metropolitan area network (WMAN) standard is designed to correct expensive communication costs in CDMA-based mobile communication systems and limited coverage problems in wireless LAN systems. Thus, the IEEE 802.16e standard can provide mobile high-speed packet access between mobile stations and the Internet service provider through the base station with cheap communication fees. To efficiently accommodate voice over IP (VoIP) services in IEEE 802.16 systems, an uplink quality of service packet-scheduling scheme is proposed, and its performance is evaluated with an NS-2 network simulator in this paper. Numerical results show that this proposed scheme can increase the system capacity by 100% more than in the unsolicited rand service (UGS) scheme and 30% more than the extended real-time polling service (ertPS) scheme, respectively.

• 산업공학
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• 제9권3호
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• pp.22-33
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• 1996

The KOREASAT satellite, the first Korean commercial communication and broadcasting satellite, has been launched in August 1995, and has started to provide the communication and preliminary broadcasting services, respectively, in March and July 1996. In this paper the network configurations and characteristics of the services which the KOREASAT satellite provides are described. The services, which are provided by the KOREASAT satellite with its twelve communication and four broadcasting transponders, are the direct broadcasting service, the video relay service including the TVRO, SNG and TV/CATV program distribution, the company-wide communication service including VSAT and TSAT, and the other services with the digital line, trunk relay, telephone line, mobile data, music broadcasting services, etc. A communication transponder has the 36MHz bandwidth and 14W output power, and a broadcasting transponder has the 27MHz bandwidth and 12OW output power.

• ETRI Journal
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• 제29권1호
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• pp.107-109
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• 2007

In location-based services, most trigger technologies have been implemented on the server side by periodically requesting the locations of mobile phones from mobile network servers. However, bottlenecks and communication interruptions occur when the servers are overloaded by trigger requests. In this letter, we propose a new multilevel location trigger specification which distributes the event detecting role to mobile phones and redesigns the location triggering into a multilevel step. Our suggested location trigger specification can reduce bottlenecks caused by triggers in a mobile core network and reduce power consumption caused by embedded GPS devices in mobile phones.

• 시스템엔지니어링학술지
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• 제17권2호
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• pp.98-105
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• 2021

As the average life expectancy is rising, the population is aging and the number of chronic diseases is increasing. This has increased the importance of healthy life and health management, and interest in mobile health services is on the rise thanks to the development of ICT(Information and communication technologies) and the smartphone use expansion. In order to meet these interests, many mobile services related to daily health are being launched in the market. Therefore, in this study, the characteristics of users who actually use mobile health services were analyzed and a predictive model applied with machine learning modeling was developed. As a result of the study, we developed a prediction model to which the decision tree and ensemble methods were applied. And it was found that the mobile health service users' continued use can be induced by providing features that require frequent visit, suggesting achievable activity missions, and guiding the sensor connection for user's activity measurement.

• 한국정보기술응용학회:학술대회논문집
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• 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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• pp.277-280
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• 2005

With the proliferation of mobile terminals, use of the Internet in mobile environments is becoming more common. To support mobility in these terminals, Mobile IPv4 is proposed and represents the standard in IPv4 environments. Authentication should be mandatory, because mobile terminals can utilize Internet services in any foreign domain. Mobile IPv4 provides symmetric key based authentication using the default HMAC-MD5. However, symmetric key based authentication creates a key distribution problem. To solve this problem, public key based authentication mechanisms have been proposed. In this paper, the performance of each of these mechanisms is evaluated. The results present that, among these mechanisms, partial certificate based authentication has superior performance, and certificate based authentication has the worst performance. Although current public key based authentication mechanisms have lower performance than symmetric key based authentication, this paper presents the possibility that public key based authentication mechanisms may be used for future mobile terminal authentication.

• 한국통신학회논문지
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• 제38A권10호
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• pp.908-917
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• 2013

본 논문에서는 기기 간 직접(device-to-device) 통신 시스템에서 근접한 디바이스의 모바일 어플리케이션 및 서비스를 발견하기 위한 디스커버리 프로토콜을 제안한다. 기기 간 직접통신 기술을 기반으로 모바일 소셜네트워크, 모바일 마케팅 등의 근접 기반 어플리케이션을 실현할 수 있다. 이를 위해 우선적으로 주변에 있는 수많은 디바이스에서 원하는 어플리케이션을 찾아내는 디스커버리 프로토콜의 설계가 필수적이다. 기반 시설이 없는 에드혹 망에서 디스커버리 프로토콜을 구현하기 위해서는 디바이스 내부의 어플리케이션 정보를 축약해서 디스커버리 코드를 생성하고 이를 주기적으로 방송하는 방법을 쓸 수 있다. 본 논문에서는 해시함수 및 블룸필터(Bloom filter)를 이용하여 디스커버리 프로토콜을 설계하고 이의 성능을 수학적으로 분석한다.

• International Journal of Internet, Broadcasting and Communication
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• 제14권2호
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• pp.63-69
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• 2022

We develop a smart tourism information system that provides smart tourism services to free independent tourists (FITs) through various content distribution channels such as mobile apps, Instagram, YouTube, and chatbots. The smart tourism information system provides location and storytelling-based tourism information, accommodation, restaurant information, and recommended travel products so that tourists can create a travel itinerary based on personalized situation awareness. The smart tourism information system also provides smart tourism services using commercial maps, navigation, and weather forecast APIs from the Korea Meteorological Administration to provide smart tour guide services to tourists who travel according to the travel itinerary. In this paper, we develop the React Native app that provides smart tourism services provided by the smart tourism information system. The smart tourism React Native app has implemented two methods: a method that directly connects to the smart tourism information system, and a method that provides services by interworking through the GraphQL Query Language developed by META (Facebook). The smart tourism React Native app implements OSMU (One Source Multi-use) by providing tourism information from mobile apps, photos from Instagram, and drone videos from YouTube as an integrated UI.

• 한국인터넷방송통신학회논문지
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• 제10권6호
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• pp.195-200
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• 2010

본 논문에서는 현재 유무선 망에서 사용가능한 새로운 모바일 네트워크 서비스인 PMOD(Private Music on Demand) 서비스를 소개하고 이를 구현한 모바일 디제이(Mobile DJ) 시스템에 대해서 소개한다. 새로운 개념의 PMOD 서비스는 유무선으로 통합되는 통신환경에서 개인의 취향 및 기호에 따라서 음악 서비스를 정비하여 사용할 수 있도록 하는 서비스로써, 사용자가 원하는 환경에서 원하는 음악서비스를 받을 수 있도록 하는 개념을 바탕으로 한다. 더불어서 이를 지원하는 모바일 디제이는 음악서비스를 개인의 취향에 맞도록 변경하는 서비스를 제공하여 기존의 단순히 듣기만 하는 음악에서 한차원 달라진 음악서비스를 제공하게 될 것이다.