• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.86-92
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• 2008

On this study, modeling works using Cone tools simulation method were made for the prediction of real fire test results such as small to large scale fire tests including ISO 5660-1, EN 13823 and ISO 13784-1. For those simulation prediction, three real fire tests were performed in advance. In addition, Real data from ISO 5660-1 test were applied to this simulation modeling. Finally, the comparative analysis between Real fire tests and Simulation results were made out. Also, the Classifying evaluation by EURO Class using EN 13501-1 were taken off.

• Journal of computational fluids engineering
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• v.16 no.2
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• pp.49-55
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• 2011

Turbulent flows with wavy wall are simulated using Residual-based Variational Multiscale Method (RB-VMS) which is proposed by Bazilves et al(2007) as new Large Eddy Simulation methodology. Incompressible Navier-Stokes equations are integrated using Isogeometric analysis which adopt the basis function as NURBS. The Reynolds number is 6760 based on the bulk velocity and averaged channel height. And the amplitude (${\alpha}/{\lambda}$) of wavy wall is 0.05. The computational domain is $2{\lambda}{\times}1.05{\lambda}{\times}{\lambda}$ in the streamwise, wall normal and spanwise direction. Mean quantities and turbulent statistics near wavy wall are compared with DNS results of Cherukat et al.(1998). The predicted results show good agreement with reference data.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.2
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• pp.303-312
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• 2012

Water supply and sewerage systems are the large-scale urban infrastructure ejecting large amount of environmental load over the life-cycle. Therefore, it is important not only to optimize in the aspect of economical superiority and process efficiency but also to consider earth scale environmental impact. This study aimed to suggest the establishment of life cycle management(LCM) system as an integrated management solution in urban water supply and sewerage systems. As a result, the methodology for LCM system consisting of life cycle assessment(LCA), life cycle cost(LCC), life cycle $CO_{2}(LCCO_{2})$ and life cycle energy(LCE) was developed. Also, several case studies using the latest statistics data of water supply and sewerage systems were carried out to investigate the field applicability of LCM.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.51-56
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• 2002

A Korea next-generation high-speed rail system represents a typical example of large- scale multi-disciplinary systems, consisting of subsystems such as train, electrical hardware, electronics, control, Information, communication, civil technology etc. The system design and acquisition data of the large-scale system must be the subject under strict configuration control and management. The system therefore, must be developed using systems engineering that is a efficient and effective methodology to design such a complex system and manage its development. This paper presents the results from a computer-aided systems engineering application to the Korea next generation high-speed railway project. Especially, the focus of the study was on requirement management and PBS management.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.163-170
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• 2002

In the form of B2C transaction, making an on-line order by using the website increases rapidly. An off-line order at the whole sale outlets is geometrically increasing. However, it is so true that both types of market are showing a tendency to become computerization. As to apply this type of computerized B2B transaction to this kind of large scale wholesale outlets, the most important fact to be considered is that there must have no data error. In addition to this, an accurate counting of actual stock is a precondition to decide a suitable amount of production and a timely delivery of goods. In this study, reducing elements of the risk that may create a difference In between actual stock and that in the computer, the integrated B2B ordering system is designed by taking actual cases an example in order to manage the information for a sale, which is conducted by various system in the large scale wholesale outlets such as E-mart, Carefour or the same kinds.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.735-741
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• 2009

This paper presents an algorithm for the permanent magnet shape optimization of a large scale BLDC(Brushless DC) motor to minimize the cogging torque. A response surface method (RSM) using multiquadric radial basis function is employed to interpolate the objective function in design parameter space. In order to get a reasonable response surface with relatively small number of sampling data points, additional sampling points are added on the basis of design sensitivity analysis computed by using FEM. The algorithm has 2 stages: the first stage is to determine the PM arc angle, and the 2nd stage is to optimize the magnet pole shape. The developed algorithm is applied to a 5MW BLDC motor to get a minimum cogging torque. After 3 iterations with 4 design parameters, the cogging torque is reduced to 13.2% of the initial one.

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.253-259
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• 2020

Most of today's large-scale cloud systems and enterprise data centers are distributing resources to improve scalability and resource utilization. NVMe-over-Fabric protocol allows submitting NVMe commands to a remote NVMe SSD through RDMA (Remote Direct Memory Access) network. It is attracting attention recently because it is possible to construct a disaggregation storage system with low latency through the protocol. However, the current I/O stack of NVMe-over-Fabric has an inefficient structure for maintaining compatibility with the traditional I/O stack. Therefore, in this paper, we propose a new mechanism to reduce I/O latency and CPU overhead by modifying I/O path of NVMe-over-Fabric to pass through legacy block layer. According to the performance evaluation results, the proposed mechanism is able to reduce the I/O latency and CPU overhead by up to 22% and 24% compared to the existing NVMe-over-Fabrics protocol, respectively.

• The Journal of Information Technology and Database
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• v.8 no.2
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• pp.61-69
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• 2001

System Integration Projects, especially in public sector, have a tendency of growing in size and duration. Under such environment the effects of IT personnel turnover becomes a serious problem. In addition a high rate of turnover hinders shill accumulation and competitiveness obtainment. In this research we explored the reasons of turnover by way of tracing IT personnel who have involved in large-scale SI projects and moved or quit before the completion of the projects. Based on previous research we identified three dimensions of variables that affected turnover : task-related dimension, human relations dimension, treatment-related dimension. We used these dimensions as a guideline for the interview and questioning exploration. Implications from the research for improving IT Personnel management are also elaborated.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.11
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• pp.577-584
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• 2002

This paper presents a novel approach based on eigenvalue perturbation of augmented matrix(AMEP) to estimate the eigenvalue for variation of controller parameter. AMEP is a useful tool in the analysis and design of large scale power systems containing many different types of exciters, governors and stabilizers. Also, it can be used to find possible sources of instability and to determine the most sensitivity parameters for low frequency oscillation modes. This paper describes the application results of AMEP algorithm with respect to all controller parameter of KEPCO systems. Simulation results for interarea and local mode show that the proposed AMEP algorithm can be used for turning controller parameter, and verifying system data and linear model.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.50-52
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• 2002

GPSS(Graphic-based Power System Simulator) had been introduced before in an ex-thesis. GPSS is a Power System Simulator that is designed to provide friendly and highly interactive Graphic User Interface (GUI). In this Paper, GPSS was improved not for the education or the test, but as the instrument for a large-scale systematic analysis. To limit the difference between a theory and practical affairs, we reformed and added a lot of functions to the GPSS. And we have verified the real-systematic data.