• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.2
• /
• pp.338-347
• /
• 1995

Equations of motion and continuity equations of a hydraulic breaker are derived. Hydraulic pressures are defined with 6 state variables corresponding to 6 control volumes. Impact analysis procedure of the piston and chisel is developed based on the finite element nodal displacement description. Computer simulation is performed with given design parameters and the results are compared with experimental results.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.181-184
• /
• 1999

This paper presents the accurate deembeding method for pad and parasitics of MOSFET device. rad effects are deembedded using THRU LINE, which is much simpler method without laborious fitting procedure compared with conventional OPEN and SHORT pad modeling. Parasitic resistance extraction uses the algebraic relation between increments of inversion layer charge and oxide capacitance. It is especially adequate for insulating gate junction device. Extracted parasitics are verified through comparing modeled and measured S parameters.

• Proceedings of the KIPE Conference
• /
• 2003.07b
• /
• pp.913-916
• /
• 2003

In many cases, ac line EMI filters are designed by trial and error method. Thus, designing a filter is a time-consuming process. To overcome the problem, the newly analytical design procedure is proposed in this paper. Using the modeling circuit of each filter components, the filter design is carried out applicable to both common-mode (CM) and differential-mode (DM). These are verified through the experimental results.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.48 no.4
• /
• pp.187-193
• /
• 1999

This study investigates the hysteresis phenomena of a Synchronous Reluctance Motor (SynRM) using coupled FEM and Preisach modeling. Preisach's model, which allows accurate prediction of hysteresis, is adopted in this procedure to provide a nonlinear solution. the computer simulation and experimental result for the i$\lambda$loci show the propriety of the proposed method.

• Journal of the Korean Data and Information Science Society
• /
• v.15 no.2
• /
• pp.395-403
• /
• 2004

The purpose of this study is to investigate the structure relationships between job satisfaction of dental residents and its related factors. The study subject was 458 dental residents who were training at 6 university dental hospitals in Korea. Data for this study were obtained by self-administrated questionnaire during 3 months. Structure equation modeling using LISREL procedure was statistically appropriate and well fitted. By the model, the socio-demographic characteristics, working condition, and status perception directly influenced on subscale satisfactions, and the subscale satisfactions positively influenced on job satisfaction.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.915-918
• /
• 2005

Advances in Information Technology and in Biomedicine have created new uses for CAD technology with many novel and important biomedical applications. Such applications can be found, for example, in the design and modeling of orthopedics, medical implants, and tissue modeling in which CAD can be used to describe the morphology, heterogeneity, and organizational structure of tissue and anatomy. CAD has also played an important role in computer-aided tissue engineering for biomimetic design, analysis, simulation and freeform fabrication of tissue scaffolds and substitutes. And all the applications require precision geometry of the organs or bones of each patient. But the geometry information currently used is polygon model with none solid geometry and is so rough that it cannot be utilized for accurate analysis, simulation and fabrication. Therefore a case study is performed to deduce a transformation method to build free form surface from a rough polygon data or medical images currently used in the application. This paper describes the transformation procedure in detail and the considerations for accurate organ modeling are discussed.

• 한국연소학회:학술대회논문집
• /
• 2000.12a
• /
• pp.24-32
• /
• 2000

A brief introduction is given on the conditional moment closure model for turbulent nonpremixed combustion. It is based on the transport equations derived through a rigorous mathematical procedure for the conditionally averaged quantities and appropriate modeling forms for conditional scalar dissipation rate, conditional mean velocity and reaction rate. Examples are given for prediction of NO and OH in bluffbody flames, soot distribution in jet flames and autoignition of a methane/ethane jet to predict the ignition delay with respect to initial temperature, pressure and fuel composition. Conditional averaging may also be a powerful modeling concept in other approaches involved in turbulent combustion problems in various different regimes.

• The KSFM Journal of Fluid Machinery
• /
• v.11 no.4
• /
• pp.32-37
• /
• 2008

In this study, we have introduced an improved equivalent modeling technique for large scale composite wind-turbine blade. Conventional or general equivalent modeling procedure may give critical error in the analysis results because of geometric coupling effects. For the analyses of structural vibration and aeroelastic problems, the accuracy of equivalent structural models is very important since it can have high numerical efficiency and various practical applications. Three-dimensional realistic composite wind-turbine blade model is practically considered for numerical study. In order to validate the effect of the mass and the stiffness of the equivalent beam model, comparison study based on the natural vibration analysis has been conducted, and the accuracy levels of the conventional and modified equivalent modeling techniques are presented.

• Journal of the Korean Society for information Management
• /
• v.14 no.2
• /
• pp.165-189
• /
• 1997

In analyzing, designing, implementing the system, the traditional modeling method lacks design procedure and specification in reflecting the functional or nonfunctional requirements perfectly and consequently. These problems are unreliable in the Library and Information System since it requires a diversity of reference methodes based on various types of data. In this paper, we modify the method partially which the OMT proposes and apply it on system development. We also prepare the object oriented modeling modified from OMT type' modeling for Library User System Requirements.

• Journal of the Korean Society of Combustion
• /
• v.5 no.2
• /
• pp.9-17
• /
• 2000

A brief introduction is given on the conditional moment closure model for turbulent nonpremixed combustion. It is based on the transport equations derived through a rigorous mathematical procedure for the conditionally averaged quantities and appropriate modeling forms for conditional scalar dissipation rate, conditional mean velocity and reaction rate. Examples are given for prediction of NO and OR in bluffbody flames, soot distribution in jet flames and autoignition of a methane/ethane jet to predict the ignition delay with respect to initial temperature, pressure and fuel composition. Conditional averaging may also be a powerful modeling concept in other approaches involved in turbulent combustion problems in various different regimes.