• Journal of Information Processing Systems
• /
• 제9권3호
• /
• pp.461-476
• /
• 2013

Recently, smart devices for various services have been developed using converged telecommunications, and the markets for near field communication mobile services is expected to grow rapidly. In particular, the realization of mobile NFC payment services is expected to go commercial, and it is widely attracting attention both on a domestic and global level. However, this realization would increase privacy infringement, as personal information is extensively used in the NFC technology. One example of such privacy infringement would be the case of the Google wallet service. In this paper, we propose an zero-knowledge proof scheme and ring signature based on NTRU for protecting user information in NFC mobile payment systems without directly using private financial information of the user.

• International Journal of Internet, Broadcasting and Communication
• /
• 제9권2호
• /
• pp.27-36
• /
• 2017

The world's unique geographical, multilingual, multiethnic, multiracial and multi religious Himalayan country Nepal has more than 100 years history on telephony service and it has been formulating appropriate policy and regulation for the adoption of new technology, introducing the competitive market environment for the overall development of Information and Communication Technology (ICT) infrastructures and application of ICT service and tools for socio-economic transformation. The Nepalese market seems to be continuously growing and having huge demand of mobile telephony and internet subscriptions trend. The ICT infrastructure development in difficult geographical area is quite challenging and thus operators are focusing mobile telephony and mobile internet services. Nepal has been doing its best effort on formulating policy and regulation, adoption key strategies for ICT sector development and at the same time joining hands with international and regional bodies such as ITU, SAARC etc for ICT sector development. Due to geographical diversity, policy and regulatory barriers in some extent, power supply constraints and low affordability from customers on ICT tools and services, Nepal has been facing challenges on ICT infrastructure development. However, the national statistics on ICT, Networked Readiness Index and ICT Development Index show that Nepal has done quite good progress and is keeping its pace on ICT development despite the these challenges. Moreover, there seems to be quite uncovered market segments on internet service and big opportunity on ICT sector development in Nepal in the days to come.

• 기술사
• /
• 제27권1호
• /
• pp.5-12
• /
• 1994

In the high degree information society of the 21st century, along with the social activity becoming much more closer, our life style will also be very much changed. Recognition for obtaining various informations rapidly will be anticipated to enhance and the progress of a mobile communication system is greatly expected. This will enable the system to give and receive ″whenever, wherever, whomever, whatsever information.″ In our country, the car telephone and personal mobile communication services of radio calling etc. are diversified by the telecommunication system reformation and by the introduction of competive principle of the hereafter of 1988. Moreover, in accordance with the tariff, the number of subscrier is rapidly increasing. On the other hand, on the utility side of business, for the realization of a mobile communication which is abundant in functional nature, not only the hitherto voice but also non voice system of data communication is being introduced. The Ministry of Communications of Korea has been expediting the effective utilization of limited frequency band of qusai microwave band etc. as a concrete measures for an ever increasing demand. At the same time, to disseminate and promote a mobile communication most effectively, convenience, economic, and safety nature of the system, and in addition to these, international standardization is considered. For constitution of a new mobile communication, the Ministry has been promoting various policies designed for the digitalization of system, utility extention for home. personal level.

• 한국통신학회논문지
• /
• 제40권11호
• /
• pp.2196-2204
• /
• 2015

이동노드의 밀집도 정보는 모바일 IT 기술의 비약적인 발전과 함께 위치기반서비스, 사물인터넷, 스마트그리드, 지능형빌딩시스템 등 최근에 확대되는 다양하고 새로운 분야에 다양하게 활용될 수 있다. 일반적으로 특정 위치에서의 무선 이동노드의 통신 가능한 수신 이동노드는 송신 이동노드의 최대 통신 거리에 따라 가변적이다. 본 논문에서에서 들로네 삼각망을 이용해서 최대 통신거리와는 무관하게 주어진 환경에서의 전체적인 노드들의 상대적 위치를 반영한 이동노드들의 밀집도를 효과적으로 계산하는 방법을 제안한다. 제안된 방법은 사물인터넷과 같이 목적, 기능에 따라 최대 통신거리가 동일하지 않은 통신 디바이스들로 구성된 통신망의 밀집도를 계산하는데 잘 활용될 수 있다. 본 논문에서 제안되는 방법은 위치기반서비스, 사물인터넷, 스마트 그리드, 지능형빌딩 시스템 등에 잘 적용될 수 있다.

• 한국철도학회논문집
• /
• 제16권6호
• /
• pp.519-527
• /
• 2013

무선 통신 기술 발전을 통하여 철도환경에서 안정적인 무선 접속과 다양한 통신 기능 제공이 가능함에 따라 철도서비스 고도화의 기반이 마련되었다. 특히, 최근의 무선 통신 기술은 향상된 철도 승객서비스뿐만 아니라 효율적이고 안전한 철도 운영을 가능하게 한다. LTE 기반의 무선통신 기술은 다양한 경제적 혜택과 높은 통신 성능을 철도 산업에 제공 가능함에 따라 세계적으로 차세대 철도 통신 시스템의 후보 기술로 각광받고 있다. 그러나 철도 통신은 열차의 안전한 운행을 위하여 매우 엄격한 철도 통신만의 요구 사항도 존재한다. 본 논문에서는 미래의 철도 통신이 반드시 갖추어야 할 요구사항과 기능을 설명한다. 또한 LTE 무선 통신 기술이 철도 분야의 통신 요구사항을 만족하는지에 대해서도 서술한다. 마지막으로 최근 진행되고 있는 차세대 철도 통합무선망의 국내외 표준화 동향과 구축일정에 대하여 설명한다.

• 한국IT서비스학회지
• /
• 제14권4호
• /
• pp.257-267
• /
• 2015

We propose a vehicle-mounted, location-aware mobile digital signage system that can be used for public transportation through mobile communication. This paper proposes the installations of the LED display panels at the backside of the bus., which display traffic information to cars behind the bus. Information to be displayed would include, but is not limited to, road information, public commercials and private commercials. We propose the system architecture and further implement the prototype of mobile digital signage system for demonstration. The system is based on the Client-Server system. Each bus has a client terminal which detects the current location by a GPS receiver and sends its location information to the server using mobile communication function. The terminal device receives advertisements and traffic information from the server and displays it to the large LCD or LED panel installed at the inside and outside of the bus. We use the Android smartphone as a client system, which inherently equipped with GPS and mobile communication function. GPS detects the location of bus and reports its geo-location data to the traffic information center server via a wireless communication network. On the server side, we developed a specially designed control server, where it communicates with the other traffic information center and updates and manages the databases contents being displayed by each position. The server contains location dependent variable information and returns selected information back to the vehicle in real time. Spatial database is used to process location based data. Server system periodically receives the real time traffic information from the road information center database. And it process the information by bus location and bus line number. In this paper, we propose a mobile digital signage service and explain the system implementation of this service.

• 한국인터넷방송통신학회논문지
• /
• 제12권6호
• /
• pp.189-197
• /
• 2012

본 논문에서는 위성과 모바일기기 간의 전파수신감도를 활용한 최적경로탐색 알고리즘을 제안한다. 일반적인 경로탐색은 최단경로를 기반으로 하기 때문에 위성을 이용하는 모바일기기의 안정적인 멀티미디어 서비스 제공이 어렵다. 제안된 알고리즘은 전파수신감도를 기반으로 하는 경로탐색을 통해 안정적인 통신환경의 제공을 목적으로 한다. 위성통신에서 수신환경에 따라 전파수신감도 변화가 심하기 때문에 수신환경의 특성을 정확하게 분석하는 것이 매우 중요하다. 전파감쇠 요인으로 대기감쇠, 수풀감쇠, 건물에 의한 감쇠 등을 적용하여 시뮬레이션을 통해 분석하고 전파수신감도로 활용한다. 제안된 알고리즘은 도심지에서 위성을 활용한 안정적인 멀티미디어 서비스 제공을 위한 최적경로를 찾을 수 있다.

• 한국IT서비스학회지
• /
• 제12권2호
• /
• pp.301-319
• /
• 2013

Wireless and mobile communication technologies enable individuals who trade stocks and bonds to use mobile-based trading services. Due to rapidly developing mobile technologies and adoption of the advanced/smart mobile devices such as smart phones and tablets, the use of mobile trading systems (MTS) have increased at an unexpected rate. Although many prior studies measured service quality on various service-related fields, there are few studies that is related to mobile trading systems compared to more traditional PC-based home trading systems. This research searches determinants of service quality for mobile trading systems and examines the effects of these factors on the intention to mobile trading systems' continuous use. Through an extensive literature review, this research finds three dimensions for mobile trading systems : interaction quality, service environment quality, and service outcome quality. The result of analysis shows that personalization, connectivity, ease of use, informativeness, and monetary value enhance the intention to continuous use. Considering environmental conditions such as the high rate of MTS adoption among individual users and stiffer competition among securities firms, these findings may help practically securities firms' shaping MTS system development strategies for individual users' continuous use and for increasing new users adoption.

• 한국인터넷방송통신학회논문지
• /
• 제11권2호
• /
• pp.171-179
• /
• 2011

오늘날 발달된 무선 네트워크 통신의 기술로 인해 많은 데이터를 빠르게 전송할 수가 있으며, 또한 더 좋은 단말기의 등장으로 멀티미디어 정보를 보여줄 수 있기 때문에 다양한 무선 인터넷 서비스가 가능하게 되었다. 따라서 SKT나 LGT와 같은 통신업체는 2.5세대 무선 기술과 스마트카드를 이용하여 온라인 쇼핑, 모바일뱅킹 등 많은 서비스를 제공하고 있다. 핸드폰을 대부분 사람들이 소유하고 있기 때문에 교통 시스템에 유용한 지불시스템으로 사용할 수 있는데, 모바일 지불 시스템이 무선 온라인 서비스로 이미 개발되어져 있기 때문이다. 본 논문에서는 모바일 교통 지불 시스템이 소개되고 있다. 운전자는 고속도로를 이용할 때 통행료를 지불해야한다. 최근에 하이패스 시스템이 개발되어 자동차는 요금을 지불하기 위해 정지하지 않고 톨게이트를 지나가면서 자동적으로 지불이 가능하다. 이러한 지불은 장착된 지불 시스템으로 인해 가능하다. 우리는 좀 더 발전된 형태로 스마트카드를 장착한 핸드폰을 지불 기기로 사용할 수 있는 시스템을 개발하였다. 개인과 금전 정보는 스마트카드에 저장되고 단말기와 OBU와의 통신은 불루투스 방식을 사용한다.

• The Journal of the Acoustical Society of Korea
• /
• 제28권2E호
• /
• pp.35-42
• /
• 2009

In this paper, we present criteria of objective measurement of speech quality to provide the mobile-VoIP services efficiently over wireless mobile internet. The mobile-VoIP service, which is based on mobility and is error-prone compared to conventional VoIP over wired network, is about to be launched, but there have not been adequate quality indexes and the Quality of Service (QoS) standards for evaluating speech quality of Mobile-VoIP. In addition, there are many factors influencing on the speech quality in packet network of which packet loss contribute directly to the overall voice communication quality. For this reason, we adopt the Gilbert-Elliot Channel Model for modeling packet network based on IP and assess the voice quality through the objective speech method of ITU-T P. 862 PESQ and ITU-T P. 862.1 MOS-LQO under various packet loss rates in the transmission channel environments. Our simulation results address the specific criteria and QoS for the mobile-VoIP services in terms of the various packet loss environments.