• Proceedings of the KIEE Conference
• /
• 2000.07c
• /
• pp.1990-1992
• /
• 2000

Isolated phase bus is, as a special bus which allows large current from a generator to main transformer, composed of main conductor, enclosure and auxiliary equipments such as insulating bellows, bus elbows, support insulator, etc. To develop this kind of high power devices, it is required to secure the technique of selection of conducting and insulating materials, basic arrangement skills, and analysis on eddy current which causes temperature increase in enclosures. By the way, these techniques are based on the analysis of electromagnetic phenomena for high voltage and large current. In this study, an electromagnetic field analysis program is developed and applied to the isolated phase bus. which could be the basic numerical method for the analysis design and modifying isolated phase bus.

• Proceedings of the KIEE Conference
• /
• 2001.10a
• /
• pp.119-121
• /
• 2001

This paper presents steady state analysis of single-phase line-start motor. 2-phase motor transformation is performed to consider the different specifications between main and auxiliary windings. The symmetrical coordinates transformation is applied to solve the unbalanced magnetic field. The validity of analysis method is verified by comparing to experiments.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.5 no.2
• /
• pp.125-132
• /
• 2010

The authors have investigated the acoustic field analysis using the Constrained Interpolation Profile(CIP) Method recently proposed by Yabe. This study has examined the calculation accuracy of the three-dimensional(3-D) acoustic field analysis using the type C CIP method. In this paper we show phase error of type C CIP method and the dependence on the wave-propagation direction in the type C CIP acoustic field analysis, and then demonstrate that it gives less-diffusive results than conventional analysis. Moreover, in comparison between type C-1 CIP, type C-2 CIP, type M CIP and FDTD, reports the memory requirements and calculation time of each method.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1996.10a
• /
• pp.113-116
• /
• 1996

Firms spend enormous efforts identifying current processes and understanding the related details before establishing new business processes in their business process redesign (BPR) projects. Considering excessive efforts required during the analysis phase and limited support to BPR projects, need for a better method is evident This article describes a method of modeling enterprise business processes bayed on common business forms. By identifying form operations and form field types, the proposed method provides redesign view on the information handling as well as the current process flows in the form of an Event-Process Chain (EPC) diagram.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.05a
• /
• pp.538-541
• /
• 2003

BSCCO superconducting thin films have been fabricated by co-deposition using IBS(Ion Beam Sputtering) method. Despite setting the composition of thin film Bi2212 or Bi2223, in both cases, Bi2201, Bi2212 and Bi2223 phase were appeared. It was confirmed the obtained field of stabilizing phase was represented in the diagonal direction of the right below end in the Arrhenius plot of temperature of the substrate and PO$_3$, and it was distributed in the rezone. The XRD peak of the generated film continuously changed according to the substrate temperature.

• Journal of the Korean Society of Systems Engineering
• /
• v.5 no.2
• /
• pp.1-9
• /
• 2009

This paper proposes an effective method on the DFILS(Design for Integrated Logistics Support) in ammunition development applying QFD(Quality Function Deployment) method. The goal of this research is to define the Design for ILS approach at the start of the ammunition development and to yield a set of reusable requirements. Based on 000mm High-Explosive(Warship ammunition) development work, a QFD software tool, CUPID, was used to analyze and define the field force's requirements. Additionally, a set of reusable requirements are identified and defined for use during the Design for ILS development phase in the next-generation ammunition development process. These set of requirements that consider both the priority and importance of the VOC(Voice of Customer) will contribute to the early phase of the ammunition development to implement the Design for ILS specialty engineering effort.

• Proceedings of the KSME Conference
• /
• 2002.08a
• /
• pp.389-392
• /
• 2002

In many industrial applications, multiphase flow analysis is the norm rather than an exception as compared to more-conventional single-phase investigation. This paper describes the implementation of the multiphase flow simulation capability in the general purpose CFD software AVL FIRE/SWIFT. The governing equations are discretized based on a finite volume method (FVM) suitable fur very complex geometry, The pressure field is obtained using the SIMPLE algorithm. Depending on the characteristics of the multiphase flow to be examined, the user can choose either the two-fluid model or an explicit interface-tracking model based on the Volume-of-Fluid approach. For truly 'multi'-phase flow problems, it is also possible to apply a hybrid model where certain phases are explicitly tracked while the other phases are handled by the two fluid model. In order to demonstrate the capability of the method, applications to the Taylor bubble flow simulations are presented.

• Journal of the Optical Society of Korea
• /
• v.12 no.3
• /
• pp.205-209
• /
• 2008

We demonstrated a simple way of evaluating the duty cycle error in periodically polled lithium niobate(PPLN) based on the method of binary phase diffraction grating. To demonstrate this method, -Z face etched PPLN of desired periods were fabricated by the standard electric field poling technique. The etched PPLN was considered as a surface-relief binary phase grating. The diffraction patterns were recorded for different spatial locations along the length of the sample. The experimentally observed efficiencies of the diffracted orders were compared with the theoretically calculated values to estimate the duty cycle error.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.9 no.2 s.25
• /
• pp.26-33
• /
• 2006

A sonar dome is basically designed and installed to protect sonar array from shocks, sea wave slaps and floating matters. The acoustic wave passing through sonar dome, however, can be distorted in magnitude and phase. This paper presents a numerical method for predicting the steady-state sound pressure on the surface of transducer array in the sonar dome and typical results of sonar beam pattern affected by sonar dome. A beam tracing model with phase information and a multi-layered elastic boundary model are involved. A full three-dimensional sonar dome is modeled as a GRP acoustic window, a rubber coated steel baffle and a rubber coated steel hull. A transducer array is modeled as thick steel cylinder. There are some assumptions such as incidence of plane wave, specular reflection on boundary and directionality of transducer element.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.11
• /
• pp.121-129
• /
• 1998

In-plane ESPI(Electronic Speckle Pattern Interferometry) was devised to measure in-plane deformations and rotation of a specimen with laser in this study. ESPI is a optical measuring method to be able to measure the deformations of engineering components and materials in industrial fields. The conventional measuring methods of surface deformations such as the strain gauge have many demerits because they are contact and point-to-point measuring ones. But that ESPI is noncontact, nondestructive and whole field measuring method can overcome previous disadvantages. We used ESPI which is sensitive to in-plane displacement for measuring in-plane deformations of a disk. And the 4-frame phase shifting method was used for the quantitative analysis. First of all, the system calibration was done due to an in-plane rotation before getting deformations of a disk. Finally we showed good agreement between the experiment results and those of the FEA(Finite Element Analysis).