• Journal of Digital Convergence
• /
• v.12 no.2
• /
• pp.243-248
• /
• 2014

The demand for messenger service goes on growing rapidly with widespread use of smartphones. Generally, the smartphone messenger provides group communication functions in which users can make the group and communicate with each other. In the mobile meeting, the attendees can participate in the meeting with use of smartphone messengers wherever they are. To make the mobile meeting put to practical use, the mobility and privacy should be ensured to attendees. To satisfy the mobility requirement, the user which is not belong to the group members should not be able to participate in the meeting. To ensure the privacy requirement, the attendees should have not to repudiate the meeting results. In this study, the mobile meeting authentication scheme is proposed which provides mobility and privacy. The proposed scheme consists of meeting group creation, group key generation, group signature and verification protocols. All attendees should have to participate in the signature verification because it is based on the challenge-response type protocol. Thus, it's not possible to collude with malicious attendees to change the meeting results.

• Proceedings of KOSOMES biannual meeting
• /
• 2017.04a
• /
• pp.248-248
• /
• 2017

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.411-413
• /
• 2012

It is noticeable that the number of newly registered Android applications increases rapidly. Such a recent trend indicates the Android platform is spreading globally. The ongoing platform upgrade might be one of the main reasons of the popularity of the Android mobile platform. Android platform 4.0 or later provides WiFi-Direct APIs that allow smart devices to communicate with each other without intermediate media. In this paper, we propose design and implementation techniques for small-scale impromptu meeting applications based on WiFi-Direct. The proposed meeting application can be used in a situation when one is difficult to connect the Internet. It also provides meeting data sharing capabilities, noting functionality, real-time remote screen control, and grouping of meeting participants. Our development results have demonstrated that the Android WiFi-Direct APIs can be effectively applied to impromptu conferencing mobile applications.

• Journal of KIISE:Information Networking
• /
• v.27 no.2
• /
• pp.131-137
• /
• 2000

The communication and collaboration of mobile agents are efficient in doing information processing in the Internet. Therefore, this paper proposes an efficient communication mechanism that support to inter-agent communications and collaborations. For the remark mentioned above, a mobile agent system provides an indirect meeting mechanism as well as an extended information pool, which has an effect on decreasing network bandwidth. In addition, some proposed communication methods can support to message multicasting so that those are effectively adapted for a model of group agent. Finally, the proposed mechanism is implemented and analyzed in the MAS, a mobile agent system model developed by the Java language.

• Electronics and Telecommunications Trends
• /
• v.38 no.1
• /
• pp.55-64
• /
• 2023

Recently, preparations for 6G have led to the increasing interest in integrated or hybrid communication networks considering low-orbit satellite communication networks with terrestrial mobile communication networks. In addition, the demand for frequency allocation for new mobile services from low-orbit small satellites to provide global internet of things (IoT) services is increasing. The operation of such satellites and terrestrial mobile communication networks may inevitably cause interference in adjacent bands and the same band frequency between satellites and terrestrial systems. Focusing on the results of the recent ITU-R WP4C meeting, this study introduces the current status of frequency sharing and interference issues between satellites and terrestrial systems, and frequency allocation issues for new mobile satellite operations. Coexistence and compatibility studies with terrestrial IMT in L band and 2.6 GHz band, operated by Inmassat and India, respectively, and a new frequency allocation study (WRC-23 AI 1.18) are carried out to reflect satellite IoT demand. For the L band, technical requirements have been developed for emission from IMT devices at 1,492 MHz to 1,518 MHz to bands above 1,518 MHz. Related studies in the 2 GHz and 2.6 GHz bands are not discussed due to lack of contributions at the recent meeting. In particular, concerning the WRC-23 agenda 1.18 study on the new frequency allocation method of narrowband mobile satellite work in the Region 1 candidate band 2,010 MHz to 2,025 MHz, Region 2 candidate bands 1,695 MHz to 1,710 MHz, 3,300 MHz to 3,315 MHz, and 3,385 MHz to 3,400 MHz, ITU-R results show no new frequency allocation to narrow mobile satellite services. Given the expected various collaborations between satellites and the terrestrial component are in the future, interference issues between terrestrial IMT and mobile satellite services are similarly expected to continuously increase. Therefore, participation in related studies at ITU-R WP4C and active response to protect terrestrial IMT are necessary to protect domestic radio resources and secure additional frequencies reflecting satellite service use plans.

• Proceedings of the Korean Information Science Society Conference
• /
• 2011.06c
• /
• pp.258-261
• /
• 2011

Living in the age of information people face problems related to information overload. Information is easy to produce, store and distribute through various communication channels, one of which is emails. With the appearance of the mobile devices, such as smart phones and tabs, people can have access to email inbox at any moment of time from everywhere. In this paper we present information extraction system with a specific goal of extracting meeting location from the announcement of seminar or conference. We apply a machine learning method (conditional random fields, CRF), train the system using annotated corpus of seminar and conference announcements and validate results by applying various extracted correction rules and patterns. Furthermore, we normalize extracted location, and reference using geo-coding databases, OpenStreetMap and Wikipedia resources to determine real geographical coordinates.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07b
• /
• pp.867-872
• /
• 2005

High-pixel-density displays are now under development to meet the needs of next-generation mobile devices; methods to more efficiently build such displays are described. Displays based on subpixel rendering and RGBW technologies, known as PenTile $Matrix^{TM}$ RGBW, are shown to offer the best approach to meeting the demanding requirements of low manufacturing cost, high brightness, and low power.

• Proceedings of KOSOMES biannual meeting
• /
• 2017.04a
• /
• pp.86-86
• /
• 2017

• Proceedings of KOSOMES biannual meeting
• /
• 2017.11a
• /
• pp.261-261
• /
• 2017

• Proceedings of KOSOMES biannual meeting
• /
• 2017.11a
• /
• pp.145-145
• /
• 2017