• The KIPS Transactions:PartA
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• v.13A no.3 s.100
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• pp.223-230
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• 2006

A MMORPG(Massively Multiplayer Online Role-Playing Game) is an online role-playing game in which a large number of players can interact with each other in the same world at the same time. Most of them require significant hardware requirements(e.g., servers and bandwidth), and dedicated support staff. Despite the efforts of developers, users often cite overpopulation, lag, and poor support as problems of games. In this paper, a dynamic load balancing method for MMORPGS is proposed. It tries to adapt to dynamic change of population by using dynamic map-partition method with VML(Virtual Map Layer) which consists of fields, sector groups, sectors, and cells. From the experimental results, our approach achieves about $23^{\sim}67%$ lower loads for each field server. By the modification to Virtual Area Layer, we can easily manage problems that come from changes of map data, resources' status, and users' behavior pattern.

• Journal of Internet of Things and Convergence
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• v.10 no.3
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• pp.1-6
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• 2024

In response to the increasing demand for unrestricted access to diverse services regardless of location, cost-effective and easily deployable Wireless Mesh Network (WMN) solutions have once again captured attention. This paper primarily addresses the implementation challenges of Autonomous Load-balancing Field-based Anycast routing+ (ALFA+) for three-dimensional (3D) WMNs. Subsequently, we evaluate the performance of ALFA+ in an 802.11-based 3D WMN testbed established within a university campus using commercial devices, thus validating the practical viability of ALFA+. While most prior research has relied on performance evaluation through virtual environment simulations, this study distinguishes itself by performance evaluations in a real-world testbed using commercial devices and providing detailed implementation-related information necessary for such evaluations. This approach holds considerable significance in assessing the actual applicability of ALFA+.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.303-305
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• 2005

In MMORPG, gamers can engage in a variety of activities with other players from all over the world. So, this kind of games has unprecedented heavy load. There are so many kind of method to balance the load of MMORPG. But. many of them are not adaptable to dynamic load variation. In this paper, we propose a dynamic map-partition method based on VML. By use of dynamic map-partition based on VML, we can easily adapt to dynamic load variation. And by changing VML. we can manage field servers within game system.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.6
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• pp.683-687
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• 2010

In this paper, we propose an anycast routing scheme for large-scale wireless mesh networks, which requires only one-hop local information with no flooding overhead. We develop an analytical model for anycast mesh networks based on an electrostatic theory. A finite difference method contributes to achieving gateway load balancing with constant control overheads. We verify the performance of the proposed scheme by simulations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.554-558
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• 2004

In this paper, we introduce noise prediction program of HVAC system to assist low-noisy design of ship's cabin. The developed program calculates sound power levels at HVAC components considering primary and secondary noise generated by fan and duct element, duct element noise attenuation, and duct break-in noise based on the authentic empirical method suggested by NEBB and acoustic power balancing method. Sound pressure level at cabin with or without ceiling system is evaluated by the diffuse-field theory considering diffuser and duct break-out sound powers. Moreover, the program provides intuitive pre- and post-processors using modem GUI functions to help efficient modeling and evaluation of cabin and HVAC component noise. To validate the accuracy and convenience of the program, noise prediction for a HVAC system is demonstrated.

• Journal of Power Electronics
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• v.19 no.5
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• pp.1171-1181
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• 2019

Modular Multilevel Converter (MMC)-based HVDC power transmission using a real-time simulator is one of the key technologies in power electronics research. This paper introduces the design methodology of a physical MMC-HVDC control system based on a Field-Programmable Gate Array (FPGA), which has the advantage of high-speed parallel operation, and validates the accuracy of MMC-HVDC control when operated with a Real-Time Digital Simulator (RTDS). Finally, this paper compares and analyzes the characteristics of capacitor voltage balancing methods such as Nearest Level Control (NLC), NLC with a reduced switching frequency, and tolerance band modulation implemented on physical control system.

• Journal of TMJ Balancing Medicine
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• v.11 no.1
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• pp.1-11
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• 2021

Dystonia is a neurological disorder characterized by involuntary and uncontrollable muscle tonus abnormalities. It is a huge burden not only to the patients and their families, but also to the field of medicine, in that there has hardly been any substantial change in the concept of and approach to this intractable disorder and therefore no breakthrough to its diagnosis, evaluation and treatment. As an effort to solve the current impasse, this review briefly summarizes the current concept, etiology, diagnosis, treatment and management, and then suggests a rather new therapeutic approach to this disorder, based on the concept of neurological balance and TMJ integrative approach. These new approaches will provide a platform for the clinicians and researchers to have a leap in the concept, diagnosis and therapeutics.

• Transactions on Electrical and Electronic Materials
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• v.6 no.2
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• pp.67-69
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• 2005

Magnetic properties of a field cooled YBaCuO superconductor beneath the toroidal permanent magnet was examined by means of improved magneto-balancing method at 77 K. Magnetic flux measurements of a toroidal magnet revealed a concave shaped field distribution with a single minimum and a null field along the axis of the torus at the point where the field reversed. The observed values of both the suspension position and the force exerted upon the superconductor specimen were in good agreement with those calculated from the magnetization curve of the specimen and the intensity of the magnetic field of the used permanent magnet.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.117-126
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• 2009

The recent interest in sensor networks has led to a number of routing schemes that use the limited resources available at sensor nodes more efficiently. These schemes typically try to find the minimum energy path to optimize energy usage at a node. Some schemes, however, are prone to unbalance of the traffic and energy. To solve this problem, we propose a novel solution: a gradient-field approach which takes account of the minimum cost data delivery, energy consumption balancing, and traffic equalization. We also modify the backoff-based cost field setup algorithm to establish our gradient-field based sensor network and give the algorithm. Simulation results show that the overhead of routing establishment obtained by our algorithm is much less than the one obtained by Flooding. What's more, our approach guarantees the basic Quality of Service (QoS) without extra spending.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.133-138
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• 1997

Belt-conveyer driving systems, which transport coal stored in the yard of a coal-fired fossil power plant to coal silos, experienced severe vibrations. From measurement, it was found that the vibrations showed beating phenomenoa and arose from hydraulic couplings installed between motors and gear boxes. In the present paper, described are results of case studies on vibration troubleshooting for the belt-conveyor driving systems: 1)resonance of the system; 2)field balancing.