• Proceedings of the KSME Conference
• /
• 2003.04a
• /
• pp.570-573
• /
• 2003

Wheels for passenger car support the car weight with tires. and they transmit rolling and braking power into the ground. Whittliing away at wheel weight is more effective to boost fuel economy that lighting vehicle body structure. A shape of hole in disk is optimized for minimizing the weight of steel wheel. Pro/ENGINEER program is used for formulating the design model. and ANSYS package is selected for analyzing the design model. It has difficulties 10 interface these commercial software directly. For combining both programs. response surface methodology is applied to construct approximation functions for maximum stresses and maximum displacements are obtained by full factorial design of five levels. This steel wheel is modeled in 14-inch diameter of rim. and wide parameter of hole in disk is only selected as design variable for reducing the weight of steel wheel. PLBA(Pshenichny·Lim-Belegundu_arora) algorithm. which uses the second-order information in the direction finding problem and uses the active set strategy. is used for solving optimization problems.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.2
• /
• pp.1027-1035
• /
• 2014

The most important design factor for portable devices is power consumption. In this paper, in the early design stage of a mobile device which measures temperature and humidity a power consumption model will be proposed and then the overall power consumption will be estimated based on this model. We will verify previously the correctness of such estimated power consumption before implementation of the real device. That is our proposed design methodology based on power consumption model. An improved design method for efficiently reducing the current consumption in the idle mode is also presented. By implementing a real prototype of the mobile device for measuring temperature and humidity, the correctness of our proposed design methodology based on power consumption modeling will be verified.

• The Journal of Information Technology and Database
• /
• v.1 no.1
• /
• pp.9-30
• /
• 1994

The objective of this paper is to give a brief review of relational design methodology, and show how a relational schema can be converted into an object-relational schema. We first introduce relational terminology and describe the relational design process along with its limitations. Next we show how the relational model can be extended to overcome these limitations : these extensions form the core of an object-relational data model ; we use the UniSQL/X data model as an example. We illustrate the process or converting a relational schema into an object-relational schema, and show the benefits of this conversion with respect to queries. The conversion process is then summarized as a set of guidelines. Finally, we make our conclusions.

• Journal of information and communication convergence engineering
• /
• v.6 no.4
• /
• pp.376-382
• /
• 2008

Developing highly cost-efficient and reliable embedded systems demands hardware/software co-design and co-simulation due to fast TTM and verification issues. So, it is essential that Platform-Based SoC design methodology be used for enhanced reusability. This paper addresses a reusable SoC platform based on OpenCores soft processor with reconfigurable architectures for hardware/software codesign methodology. The platform includes a OpenRISC microprocessor, some basic peripherals and WISHBONE bus and it uses the set of development environment including compiler, assembler, and debugger. The platform is very flexible due to easy configuration through a system configuration file and is reliable because all designed SoC and IPs are verified in the various test environments. Also the platform is prototyped using the Xilinx Spartan3 FPGA development board and is implemented to a single chip using the Magnachip cell library based on $0.18{\mu}m$ 1-poly 6-metal technology.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.4
• /
• pp.134-140
• /
• 1998

The authors have shown that the performance of discrete-time observer-based monitoring systems can be represented by the performance index k$_2$(P) (condition number of the eigensystem P of the observer matrix in terms of L$_2$ norm). The observers with the minimized performance index can be defined as robust observers in the sense that the observer performance can be guaranteed in harsh environments. In this paper, based on the performance index, a design methodology for the robust discrete-time observer is developed. Similar to the continuous-time case, the methodology determines the structure and eigenvalues of the observer matrix simultaneously. A complete design procedure is given for single-output case and is illustrated with a spindle-driver example. The simulation results demonstrate the improved performance compared with a traditional pole-placement observer technique.

• Journal of the Korean Society for Precision Engineering
• /
• v.32 no.1
• /
• pp.107-111
• /
• 2015

This paper proposes an optimal design for a precision motion stage employing a parallelogram flexure hinge. The voltage applied to the piezo element produces motion that is amplified through a 3-stage amplification structure. Especially, instead of the generally used conic section flexure hinge a parallelogram shaped flexure hinge is used that improves the flexibility of the lever. An Finite Element Analysis is performed on each motion stage lever where optimal design was achieved using Response Surface Methodology(RSM).

• Proceedings of the KIEE Conference
• /
• 1993.07b
• /
• pp.1286-1288
• /
• 1993

An analytical method for the optimum design of the minimum die size in power MOSFETs is presented. The proposed methodology considers the thermal resistance of the package and gives the minimum die area for desired drain current levels. The results are compared with experimental data and it is found that the die size mar be reduced if it is designed according to the proposed design procedure.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2006.05a
• /
• pp.894-898
• /
• 2006

A model, which can analyze the hydrological performance for small hydropower(SHP) plants having no flow duration characteristics has been studied and developed. System performance of existing SHP plant under operating was analyzed by using the developed model. The annual operational rate of SHP plant showed that the data were in good agreement with predicted results from the model. Based on these results, several SHP sites to be exploited were selected and the performance characteristics were analyzed by using the developed model. Also, primary design values such as design flow rate, plant capacity, and operational rate were suggested. As a result, it was found that the methodology used in this study is useful tool to predict the hydrological system performances of SHP sites.

• Journal of Magnetics
• /
• v.20 no.4
• /
• pp.413-420
• /
• 2015

In this study, we present a comparison of multistage axial flux permanent-magnet machines (AFPMs) with different topologies for use as 100 W-class portable generating systems. Three topologies were selected, and the maximum power density and high level of efficiency were achieved by following the response surface methodology (RSM) in the design. Three-dimensional finite element analysis (FEA) was used to conduct numerical experiments to obtain the optimum design using the RSM and suggest a proper configuration of the portable generating system.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.483-483
• /
• 2000

The Fuzzy Preview Control (FPC) design methodology using I-PD Preview Control (IPC) and Optimal Preview Control (OPC)[6] are discussed in this paper. First we show a new fuzzy controller with single input single output, and build a relationship between it and the I-PD Control proposed by Kitamari, as well as Optimal Control with some specific equations. We also give the stability analysis with Lyapunov theorem. On this way, we can design a Fuzzy I-PD Controller (FIC) very easier and more effective. Then, preview control element design methodology of FCP was given according to IPC and OPC. Third, to make the system more rapidly and more little overshooting, two factors are given to adjust the controller's properties. At last, the performance of FPC is revealed via computer simulation using a nonlinear plant.