• Journal of Korean Society for Quality Management
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• v.29 no.1
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• pp.47-61
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• 2001

The ever increasing demands for enhanced competitiveness of engineered products require a "designing-in-quality" strategy that can effectively and efficiently incorporate multiple design objectives into design. Robust design can be viewed as a multi-characteristic design problem requiring tradeoffs between mean and variance characteristics. Firstly this paper analyzes the intrinsic preference of the traditional SN ratio on mean and variance, and secondly presents a new design metric for a robust design using concepts from utility theory to accurately capture designer′s intent and preference on mean and variance. The steps to apply the proposed design metric as the robust design criterion in an orthogonal array based engineering experimentation is presented with the aid of a demonstrative case study. The performance of the proposed design metric is tested, and the results are discussed.

• Environmental and Resource Economics Review
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• v.9 no.4
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• pp.747-771
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• 2000

This paper reports the results of a study to elicit willingness to pay (WTP) for changes in health risks from exposure to As, Pb, THM in tap water using experimental market method. The experimental market method, compared with other non-market valuation methods, allows us to use incentive compatible demand revealing scheme, to acquire market-like experience through repetitive auctions, and to incorporate learning process by providing new information during the session. Participants seemed to utilize the objective risk information in a 'rational' manner, and to change their WTP bids accordingly. Moreover they were able to reduce the 'ambiguity' in risk perception processes when objective risk probabilities provided are quite different from their subjective perceptions. Nonetheless, anchoring effects appeared to be still persistent in spite of market-like experience and learning opportunity. And implicit values entailed by WTP bid/risk tradeoffs indicate a wide variation in values across alternative risk reductions and overrated responses to very small risk reductions.

• Nuclear Engineering and Technology
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• v.43 no.4
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• pp.383-390
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• 2011

Nuclear power has become an essential part of electricity generation to meet the continuous growth of electricity demand. A Sodium-cooled Fast Reactor (SFR) was developed to extend uranium resource utilization under a growing nuclear energy scenario while concomitantly providing a nuclear waste management solution. Key questions in this scenario are when to introduce SFRs and how many reactors should be introduced. In this study, a methodology using Linear Programming is employed in order to quantify an optimized growth pattern of a nuclear energy system comprising light water reactors and SFRs. The optimization involves tradeoffs between SFR capital cost premiums and the total system U3O8 price premiums. Optimum nuclear growth patterns for several scenarios are presented, as well as sensitivity analyses of important input parameters.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.640-643
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• 2004

As the size of a network increases, the network complexity and maintenance cost is high. In literatures, many cost factors of multistage interconnection networks were intensively investigated. However, in some parts, these types of cost definition are not satisfactory enough since they don't relate the cost measure to technology closely and also fail to incorporate exact tradeoffs in designing the network. In this paper, we propose some cost effective measures which combine the cost factors with performance-related reliability measures, and compare several networks for a guidance to select a certain case depending on the principal concerns for use.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.1
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• pp.77-82
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• 2010

An analytical method for robust design of the multi-loop proportional-integral (PI) controller is proposed for various types of multi-delay processes. On the basis of the direct synthesis and generalized IMC-PID approach, the analytical tuning rules of the multi-loop PI controller are firstly derived for achieving the desired closed-loop response, and the structured singular value synthesis is then utilized for the tradeoffs between the robust stability and performance by adjusting only one design parameter (i.e., the closed-loop time constant). To verify the superiority of the proposed method, the simulation studies have been conducted on a wide variety of multivariable processes. The multi-loop PI controller designed by the proposed method shows a fast, well-balanced and robust response with the minimum integral absolute error (IAE) in compared with other renowned methods.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1736-1739
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• 2002

The advanced in semiconductor, hardware, and software technologies enables the integration of more com- plex systems and the increasing design complexity. As system design complexity becomes more complicated, System-level design based on the If block and processor model is more needed in most of the RTL level or low level. In this paper, we present a novel approach fur the system-level design, which satisfies the various required constraints and an optimization method of image encoder based on codesign of function, algorithm, and architecture. In addition, we show an MPEG-4 encoder as a design case study. The best tradeoffs between algorithm and architecture are necessary to deliver the design with satisfying performance and area constraints. The evaluations provide the effective optimization of motion estimation, which is in charge of an amount of performance in the MPEG-4 encoder module.

• ETRI Journal
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• v.26 no.5
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• pp.413-422
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• 2004

This paper investigates the impacts of array weight errors (AWE) in an antenna array (AA) on a parallel interference cancellation (PIC) receiver in uplink synchronous and asynchronous direct sequence code division multiple access (DS-CDMA) systems. The performance degradation due to an AWE, which is approximated by a Gaussian distributed random variable, is estimated as a function of the variance of the AWE. Theoretical analysis, confirmed by simulation, demonstrates the tradeoffs encountered between system parameters such as the number of antennas and the variance of the AWE in terms of the achievable average bit error rate and the user capacity. Numerical results show that the performance of the PIC with the AA in the DS-CDMA uplink is sensitive to the AWE. However, either a larger number of antennas or uplink synchronous transmissions have the potential of reducing the overall sensitivity, and thus improving its performance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.59-66
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• 1997

When using hazard machines such as automobiles, operators receive information through eye. The operater must process the information quickly and properly in order to perform the operation efficiently and safely. Therefore, several techniques to measure the eye movements have been developed. The choice of an optimum method for a situation depend on the type of data needed, the necessity of knowing the position of the observer's head, and the tradeoffs of precesion versus comfort. The goal of this study is to review the present status of the measure and the eye movement measuring techniques, to investigate the development trend, and to show that some measure and eye movement measuring techniques are adquate for some task.

• Proceedings of the KIEE Conference
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• summer
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• pp.1217-1219
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• 2004

This paper presents a modified PI control algorithm using pole placement for DC-to-DC converter of a magnetic levitation system(MAGLEV). The gains of the control algorithm were selected based on pole locations formulated from a prototype Bessel transfer function model. The design incorporate tradeoffs in DC-to-DC converter hardware parameters and pole locations. In order to confirm the superiority of the proposed pole selection and controller, simulation and experiment results are presented.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.418-420
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• 2007

When the magnetic levitation system(MAGLEV) initially rise, The MAGLEV has a weak point that is very large variation of the electric current. In this paper, The author applied the multi-loop-control to stably control the magnetic levitation system(MAGLEV). The gains of the control algorithm were selected based on pole locations formulated from a prototype Bessel transfer function model. The design incorporate tradeoffs in DC-to-DC converter hard-ware para-meters and pole locations. In order to confirm the superiority of the proposed pole selection and controller, MATLAB simulation and experiment results are presented.