• ETRI Journal
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• v.36 no.4
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• pp.554-563
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• 2014

The burgeoning growth of real-time applications, such as interactive video and VoIP, places a heavy demand for a high data rate and guarantee of QoS from a network. This is being addressed by fourth generation networks such as Long-Term Evolution (LTE). But, the mobility of user equipment that needs to be handed over to a new evolved node base-station (eNB) while maintaining connectivity with high data rates poses a significant challenge that needs to be addressed. Handover (HO) normally takes place at cell borders, which normally suffers high interference. This inter-cell interference (ICI) can affect HO procedures, as well as reduce throughput. In this paper, soft frequency reuse (SFR) and multiple preparations (MP), so-called SFRAMP, are proposed to provide a seamless and fast handover with high throughput by keeping the ICI low. Simulation results using LTE-Sim show that the outage probability and delay are reduced by 24.4% and 11.9%, respectively, over the hard handover method - quite a significant result.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2382-2388
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• 2014

To provide network reliability in indoor wireless communication systems, we should resolve the problem of unexpected network failure rapidly. In this paper, we propose an adaptive resource management (ARM) scheme to support seamless connectivity to users. In consideration of system throughput and user fairness simultaneously, the ARM scheme adaptively determines the set of healing channels, and performs scheduling and power allocation iteratively based on a constrained non-convex optimization technique. Through intensive simulations, we demonstrate the superior performance results of the proposed ARM scheme in terms of the average cell capacity and user fairness.

• Journal of Information Technology Services
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• v.22 no.6
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• pp.115-132
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• 2023

This study aimed to propose application directions for South Korea's digital health policy by conducting a literature review, data analysis, and examining foreign cases. The objective was to enhance the healthcare rights of individuals with disabilities, considering the potential expansion of the digital health policy. The findings indicate that digital health holds significant promise in improving mobility and accessibility for the healthcare rights of disabled individuals in Korea. However, addressing the digital gap is crucial for achieving smooth utilization. To ensure seamless use of the digital health system, it is imperative to attain digital inclusion, encompassing digital technology, connectivity, and accessibility. Additionally, establishing governance for digital health and expanding infrastructure for affordable access to high-quality internet are essential. Despite the study's limitations arising from relying on literature research, it is anticipated that the findings can serve as foundational data for preemptive responses and provide insights into the direction of the government's digital health policy to enhance the healthcare rights of individuals with disabilities.

• Journal of Information Technology Applications and Management
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• v.31 no.3
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• pp.93-104
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• 2024

This study conducts an in-depth analysis of user reviews from three leading metaverse platforms - Minecraft, Roblox, and Zepeto - using advanced topic modeling techniques to uncover key factors for business success. By examining a substantial dataset of user feedback, we identified and categorized the main themes and concerns expressed by users. Our analysis revealed that common issues across all platforms include technical functionality problems, user engagement and interest, payment concerns, and connection difficulties. Specifically, Minecraft users highlighted the importance of adventure and creativity, Roblox users expressed significant concerns about security and fraud, and Zepeto users focused heavily on the fairness of the in-game economy. The findings suggest that for metaverse platforms to achieve sustained success, they must prioritize the resolution of technical issues, enhance features that foster user engagement, ensure reliable connectivity, and address platform-specific concerns such as security for Roblox and payment fairness for Zepeto. These insights provide valuable guidance for developers and business strategists, emphasizing the need for robust technical infrastructure, engaging and diverse content, seamless user access, and transparent and fair economic systems. By addressing these key areas, metaverse platforms can improve user satisfaction, build a loyal user base, and secure long-term success in an increasingly competitive market.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.3
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• pp.183-192
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• 2013

As a worldwide trend, the spatial information that is established by country, institution and purpose is integrated into the data with a single spatial reference to improve the data connectivity and usability. In this study, a new national single origin plane rectangular coordinate system was studied to efficiently respond to the changes in the spatial reference according to the introduction of a new national geodetic standard and to the demand of seamless data service in the spatial information sector. For this purpose, the Korean Peninsula was set as the projection region and the projection distortion in the projection region was analyzed. The projection parameters were defined to homogenize and minimize the projection distortion, and their standardization and registration on the international organizations were conducted. The study on the required optimal projection equation resulted in the Hooijberg projection equation and projection parameters (${\Phi}$, ${\lambda}$, K, N, E) resulted in $38^{\circ}N$ and $128^{\circ}E$ projection origin, and a scale factor of 0.99924. The proper false northing and easting were 700,000m N and 400,000m E, respectively, considering the introduction of country station index system.

• Convergence Security Journal
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• v.8 no.3
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• pp.41-49
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• 2008

Other server based-application and the need of more complex interaction is required with functional strengthening and variational uses of mobile device. And mobile environments make a problem of continuous of web-service by making a problem of instance cutting between web-server and mobile device which acts as a client because of mobility. Therefore, this paper embodies a framework which keeps security and connectivity between HTTP based web-service and mobile device, and is for connection to web-service of mobile device which uses WAP in a standard protocol based mobile environment of mobile web-service for continuous web-service. This paper is analyzed in the same standard condition to compared functional delay which is based on HTTP and WAP access, and data transmission volume. Also it investigates improvement of execution overhead which is brought by interaction process.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.28-36
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• 2016

ID federation provides users various benefits such as employing multiple services with only single authentication and mitigating management burden of service providers that individually preserve account information of users. To keep up with this international trend, efforts for making the domestic ID federation is ongoing to provide users in the domestic research and education community seamless network connectivity and to support tetherless extension of research environment. In this paper, we analyze the foreign ID federation policies and compare them as a underlying work for making the domestic ID federation. Besides, we suggest some contents that should be included in the domestic ID federation policy. To activate the coming domestic ID federation, we need to first have a well-made federation policy. Then, we need to aggressively promote the domestic ID federation, develop various and fascinating services, and build a convenient support system for technology and service.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.7
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• pp.2389-2413
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• 2015

High data rates in long-term evolution (LTE) networks can affect the mobility of networks and their performance. The speed and motion of user equipment (UE) can compromise seamless connectivity. However, a proper handover (HO) decision can maintain quality of service (QoS) and increase system throughput. While this may lead to an increase in complexity and operational costs, self-optimization can enhance network performance by improving resource utilization and user experience and by reducing operational and capital expenditure. In this study, we propose the self-optimization of HO parameters based on fuzzy logic control (FLC) and multiple preparation (MP), which we name FuzAMP. Fuzzy logic control can be used to control self-optimized HO parameters, such as the HO margin and time-to-trigger (TTT) based on multiple criteria, viz HO ping pong (HOPP), HO failure (HOF) and UE speeds. A MP approach is adopted to overcome the hard HO (HHO) drawbacks, such as the large delay and unreliable procedures caused by the break-before-make process. The results of this study show that the proposed method significantly reduces HOF, HOPP, and packet loss ratio (PLR) at various UE speeds compared to the HHO and the enhanced weighted performance HO parameter optimization (EWPHPO) algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.660-666
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• 2014

In this paper, we consider a classification criteria of sensor nodes based on equipment function, and propose a routing search algorithm between node when an IP-USN is applied inside a ship. whereas a tree-type routing algorithm is applied to the limited mobile enviroment, such as engine room or machine room, a mesh-type routing alogrithm is to free mobile enviroment, such as passager corridor liviing quarters or restanrats areas. For mesh-type routing, it is necessary to maintain a seamless route path between a sink node and sensor nodes for which we consider a novel message exchange periodically. We proposed a new message, RDES message, which is issued periodically to update the topology of sensor node and check a connectivity between nodes.

• The Journal of Korean Association of Computer Education
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• v.15 no.5
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• pp.55-62
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• 2012

With the development of mobile communications and Internet technology, there is a strong need to provide seamless and fast connectivity for roaming devices. Generally, the mobile host (MH) may have several available networks when entering a new wireless area. However, the standard of decision for user's internet connection is provided only the subsystem identification (SSID) and signal strength of access point (AP). These two standards could not enough to decide optimal AP to the MH. Therefore, to decide the optimal AP, more information is needed. In this paper, we present additional information such as status of MH, capacity, current load, and depth of network hierarchy, by router advertisement message at layer 3. Also, we proposed decision engine (DE) on the MH that analyzes APs and decides the optimal AP automatically by AP's status information. For the MH, wireless connection period is increased, the power consumption is decreased, and the signaling overhead is reduced. For AP and router, the load balancing is provided and the network topology can also be more efficient.