• Proceedings of the Safety Management and Science Conference
• /
• 2009.11a
• /
• pp.411-415
• /
• 2009

There are some definitions of cloud computing but it can be defined as utilization of personal computers, servers and softwares in one cluster for approaches to the use of shared computing resources. Nowadays the applications of cloud computing are rapidly increasing because of its merits on economic aspect, connectivity convenience, storage space and so on. The main objective of this paper is to find an effective methodology as an initial stage for applications of cloud computing in a real life. Therefore this paper addresses worldwide reviews on cloud computing.

• 한국전산유체공학회:학술대회논문집
• /
• 1996.05a
• /
• pp.118-124
• /
• 1996

When computing the flow around complex three dimensional configurations, the generation of the grid is the most time consuming. This paper presents a survey of the grid generation technique. The technique for treating problems arising in gird generation for complex geometries is addressed. A general procedure for generating boundary conforming grids is included

• 한국전산유체공학회:학술대회논문집
• /
• 2001.10a
• /
• pp.174-181
• /
• 2001

The Gird is a communication service that collaborates dispersed high performance computers, large-scale databases and modern equipments so that those can be shared and worked together. In this paper. CFD research based on National Grid project is discussed. To validate the Grid technology, the flow past ONERA M6 wing and the flow past infinite wing are simulated on the National Grid testbed.

• Journal of Computing Science and Engineering
• /
• v.9 no.2
• /
• pp.39-50
• /
• 2015

Genetic algorithm (GA) and particle swarm optimization (PSO) are two excellent approaches to multimodal optimization problems. However, slow convergence or premature convergence readily occurs because of inappropriate and inflexible evolution. In this paper, a novel optimization algorithm with a flexible grid optimization (FGO) is suggested to provide adaptive trade-off between exploration and exploitation according to the specific objective function. Meanwhile, a uniform agents array with adaptive scale is distributed on the gird to speed up the calculation. In addition, a dominance centroid and a fitness center are proposed to efficiently determine the potential guides when the population size varies dynamically. Two types of subregion division strategies are designed to enhance evolutionary diversity and convergence, respectively. By examining the performance on four benchmark functions, FGO is found to be competitive with or even superior to several other popular algorithms in terms of both effectiveness and efficiency, tending to reach the global optimum earlier. Moreover, FGO is evaluated by applying it to a parameter decision in a least squares support vector machine (LS-SVM) to verify its practical competence.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.8
• /
• pp.1950-1963
• /
• 1995

A modification of the approximate-factorization method is made to accelerate the convergency rate and to take sufficiently large Courant number without loss of accuracy. And a stable implicit finite-difference scheme for solving the incompressible Navier-Stokes equations employed above modified method is developed. In the present implicit scheme, the volume fluxes with contravariant velocity components and the pressure formulation in curvilinear coordinates is adopted. In order to satisfy the continuity condition completely and to remove spurious errors for the pressure, the Navier-Stokes equations are solved by a modified SMAC scheme using a staggered gird. The upstream-difference scheme such as the QUICK scheme is also employed to the right hand side. The implicit scheme is unconditionally stable and satisfies a diagonally dominant condition for scalar diagonal linear systems of implicit operator on the left hand side. Numerical results for some test calculations of the two-dimensional flow in a square cavity and over a backward-facing step are obtained using both usual approximate-factorization method and the modified one, and compared with each other. It is shown that the present scheme allows a sufficiently large Courant number of O(10$^{2}$) and reduces the computing time.

• The KIPS Transactions:PartA
• /
• v.13A no.1 s.98
• /
• pp.35-44
• /
• 2006

Grid accounting model is necessary to support the demand and supply of id resource. Most grid accounting systems currently in use intrude upon site autonomy by modifying local accounting systems or calculate the cost of grid service without regard to site price policy. In this paper we propose and design Grid accounting model based on site price policy. This model assures autonomy of sites participating in gird computing and be able to actively cope with diverse billing services. Also this proposed model enables to provide RUS to Grid entities by transforming basic accounting information into GGF-UR format and allows this entities to exchange resource usage information. In this paper, proposed Grid accounting model enables sites to have autonomy of them and is evaluated for business model to enforce elaborate charging policy, compared with other systems.

• KIPS Transactions on Computer and Communication Systems
• /
• v.7 no.11
• /
• pp.269-274
• /
• 2018

MMORPG is a role-playing game that tens of thousands of people access it online at the same time. Users connect to the server through the game client and play with their own characters. If the user moves to a management area of another server beyond the area managed by the server, the user information must be transmitted to the server to be moved. In an actual game, the user is required to synchronize the established and the transferred information. In this paper, we propose a migration agent server in the virtual systems. We implement a seamless virtual server using the grid method to experiment with seamless server architecture for virtual systems. We propose a method to minimize the delay and equalize the load when the user moves to another server region in the virtual environment. Migration Agent acts as a cache server to reduce response time, the response time was reduced by 50% in the case of 70,000 people.

• Proceedings of the Korea Contents Association Conference
• /
• 2007.11a
• /
• pp.560-564
• /
• 2007

Korea Basic Science Institute(KBSI) has three general electron microscopes including High Voltage Electron Microscope(HVEM) which is the only one in Korea. Observed images through an electron microscope are what they are tilted by each step and saved, offering the more better circumstances for observers, a reconstruction to 3D could be a essential process. In this process, a warping method decreases distortions maximumly of avoided parts of a camera's focus. All these image treatment processes and 3D reconstruction processes are based on an accompaniment of a highly efficient computer, a number of Grid Node Personal computers share this process in a short time and dispose of it. Grid Node Personal computers' purpose is to make an owner can share different each other and various computing resources efficiently and also Grid Node Personal computers is applying to solve problems like a role scheduling needed for a constructing system, a resource management, a security, a capacity measurement, a condition monitoring and so on. Grid Node Personal computers accomplish roles of a highly efficient computer that general individuals felt hard to use, moreover, a image treatment using the warping method becomes a foundation for reconstructing to more closer shape with an real object of observation. Construction of the electron microscope volume 랜더링 system based on Grid Node Personal computer through the warping process can offer more convenient and speedy experiment circumstances to observers, and makes them meet with experiment outcome that is similar to real shapes and is easy to understand.