• Journal of the Korea Society of Computer and Information
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• v.18 no.2
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• pp.59-68
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• 2013

Efficient resource management and hand-over schemes are necessary to maintain consistent QoS because it may be severely defected by some delay and information loss during hand-over in LTE-Advanced networks. This paper proposes a resource management scheme based on the load control to support consistent QoS for heterogeneous services during hand-over in OFDMA based systems. Various multimedia services with different requirements for resource are able to be serviced simultaneously because service continuity can be provided by our proposed scheme. Simulation results show that it provides better performances than the conventional one with the measure of hand-over failure rate and packet loss rate.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.3
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• pp.483-496
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• 2024

This paper proposes a location-based inter-beam handover event considering terminal mobility to enhance the service quality for terminals in satellite networks. The terminal continuously measures the distance between the serving cell and neighboring cell centers, and checks whether the handover event condition is satisfied, taking into account the terminal's velocity. Performance analysis results demonstrate that the proposed location-based handover event reduces the frequency of unnecessary handover event triggering compared to the conventional received signal strength-based handover event, thereby improving the service continuity of the terminal.

• Korean Journal of Social Welfare Studies
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• v.45 no.2
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• pp.31-63
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• 2014

Recently interest in civic engagement and civic service is increasing. However, in Korea, few studies have focused on civic service. This might be on account of general awareness that civic service is fundamentally different from the basic spirit of voluntary work, while interest in paid volunteer work is on the rise. Thus, it is necessary to examine whether civic service is the real antipode of volunteer work. Under this kind of critical viewpoint, this study aims to analyze civic service based on the attributes of voluntary work and civic service. The major findings are as follows. Firstly, contrary to common belief, civic service has not been established to go beyond the principle of voluntary and unpaid characteristics of volunteer work. Rather, some voluntary work has broken out of principle of voluntary activities. Secondly, civic service and volunteer work might be characterized as different not due to spontaneity and unpaid service but the structural characteristics of the goal, continuity and formality. Furthermore, the reason for the soft landing of civic service in the United States is not because they have supported the reimbursement of expenses and the provision of stipends. Rather, it is because their long-term activities have promoted real community development for the purpose of finding solutions to social problems, and they have derived a sense of pride and satisfaction from social recognition and rewards for their contributions.

• Journal of Korea Multimedia Society
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• v.12 no.11
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• pp.1509-1520
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• 2009

Contrary to ubiquitous environments, indoor computing environments like home network doesn't support user mobility. This paper suggests UPnP A/V multimedia system using prediction of mobility for adaption of seamless multimedia service. The multimedia system enables indoor mobile users to play multimedia contents by transferring the current session to an adjacent device automatically. The system represents users' contextual information by Five Ws and One H model, and predicts user's movements by using contextual information and transitions of locations. The prediction basically includes multiple locations so that it improves accuracy of prediction. We evaluated the suggested system using in accuracy of prediction, time for prediction, handover time for service, and the system showed that adapt ion of seamless multimedia service was enabled by using prediction of mobility on mobile user.

• Journal of the Korean School Mathematics Society
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• v.23 no.1
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• pp.89-109
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• 2020

This study aims to improve teacher education by analyzing the causes and backgrounds of which pre-service mathematics teachers experience learning difficulties on the topic of discrete mathematics. To this end, we conducted a questionnaire and an evaluation on the topic of discrete mathematics, and the obtained data were analyzed. The results show that (1) pre-service mathematics teachers need to share their perceptions of the need for discrete mathematics education; (2) a review of the adequacy of the discrete mathematical content and its credits are required; (3) the causes of their learning difficulties need to be looked at from a different perspective than the learning factors. And two implications were obtained. First, it is necessary to study the systematicity and sequence of content elements of discrete mathematics in the aspect of its continuity of curriculum of secondary school and university. Second, it is required consideration for adjusting the ratio of discrete mathematics to secondary teachers' employment examination.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.335-342
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• 2018

The search service, which is a core service of the portal site, presents search queries that are rapidly increasing among the inputted search queries based on the highest instantaneous search frequency, so it is difficult to immediately notify a search query having a high degree of interest for a certain period. Therefore, it is necessary to overcome the above problems and to provide more intelligent information retrieval service by bringing improved analysis results on the change of the search queries. In this paper, we present the criteria for measuring the interest, continuity, and attention of real-time search queries. In addition, according to the criteria, we measure and summarize changes in real-time search queries in hours, days, weeks, and months over a period of time to assess the issues that are of high interest, long-lasting issues of interest, and issues that need attention in the future.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.3
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• pp.347-370
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• 2022

Most public library websites provide unstructured cultural program data, which cannot be produced and utilized systematically as bibliographic information. It is not sufficiently used in existing library big data research or cases, and there is a risk of disappearing when the website is reorganized or the person in charge is changed. This study developed a data schema that can be used in conjunction with bibliographic data by collecting and analyzing cultural programs and community service data produced in an unstructured manner and proposed to share and utilize public library cultural programs and community service data, and establish a library big data platform that can serve as an information channel between librarians who are cultural program planners. Library program data posted on the library website can be integrated and managed through the platform, securing continuity of work, and systematically managing and preserving the specialized service history of individual libraries.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.12
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• pp.27-37
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• 2003

In the next generation Internet(NGI) based on dense wavelength division multiplexing(DWDM) technology, QoS RWA considering various QoS parameters of DWDM networks is regard as one of the key issues in providing real-time multimedia services. However, finding a qualified path meeting multi-constraints is generally NP-complete problem. It is insufficient for QoS RWA researches in DWDM networks that must consider QoS parameter as well as wavelength-continuity constraint. This paper proposes qualified path routing (QPR) algorithm with minimum computation and implementation complexity based on flooding method to accomplish QoS routing and wavelength assignment (RWA). We also introduce a QoS-based RWA mechanism considering multi-constraint such as optical signal quality attributes, survivability and wavelength-continuity constraint combined with proposed routing algorithm. Simulation results show superior efficiency of the proposed algorithms in terms of blocking probability, routing overhead and survivability ratio.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.177-182
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• 2016

Geofence is a generic concept for describing geographic aspects of PoI(Point of Interest) enabling users to proactively induce context-based actions. However there is no need to maintain continuity when you reflect geofence in case of temporary events, accidents and isolation. Therefore we propose a geofence platform so-called TemG by adding time-limited information to support PoI. The proposed geofence platform TemG ensures the persistency and continuity of geofence. Furthermore, the proposed TemG can not only provide to automatically activate or deactivate the specified geofence during a period of timestamp but also support to the basic context-aware service knowing in/out in the zone. In the near future, the proposed TemG will be need to extend HPS(Hybrid Positioning System) for IoT(Internet of Things).

• Aerospace Engineering and Technology
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• v.5 no.2
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• pp.16-26
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• 2006

GNSS is a satellite-based radio navigation aid. For using it in civil air navigation area, any GNSS service should meet the requirements of accuracy, integrity, continuity and availability in each flight phase established by ICAO. In this study, a remote integrity monitoring system(RIMS) for GNSS are proposed and explained to utilize it in the design of GNSS augmentation system such as GBAS and GRAS. The RIMS consists of signal-in-space receiving subsystem and signal processing subsystem. Each GPS receiver is connected to Host PC by the serial to ethernet converting device which is able to convert serial port connection to LAN port connection in order to exchange information via the internet. We can overcome the siting limitation of GPS receiver and antenna, and reduce signal loses in the cable between GPS antenna and receiver. This system is providing the development environment for GBAS CAT-I system.