• Journal of Korean Society for Quality Management
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• v.26 no.4
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• pp.88-100
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• 1998

Robust design in industry is an a, pp.oach to reducing performance variation of quality characteristic value in products and processes. Taguchi has used the signal-to-noise raio(SN) to achieve the a, pp.opriate set of operating conditions where variablity around target is low in the Taguchi parameter design. Taguchi has dealt with having constraints on both the mean and variability of a characteristic (the dual response problem) by combining information on both mean and variability into an SN. Many Statisticians criticize the Taguchi techniques of analysis, particularly those based on the SN. In this paper we propose a substantially simpler optimization procedure for robust design to solve the dual response problems without resorting to SN. Two examples illustrate this procedure in the two different experimental design(product array, combined array) a, pp.oaches.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.7
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• pp.45-52
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• 2006

A cyclic viscoelastic-viscoplastic constitutive model for clay is incorporated into an effective stress based seismic response analysis to describe viscous effect of clay layer to sand layer during earthquake. The seismic response against main shock of 1995 Hyogoken Nambu Earthquake is analyzed in the present study. Acceleration responses in both clay layer and just upper liquefiable sand layer are damped due to viscous effect of clay. A cyclic viscoelastic-viscoplastic constitutive model for clay was implemented into a FEM code, and $Newmark{\beta}$ method was employed for the time discretization in the finite element formulation. Seismic responses were simulated by numerical method with recorded data at Port Island, Kobe, Japan. As results of this study, it was found that a cyclic viscoelastic-viscoplastic constitutive model can give good description of dynamic behavior characteristics including viscoelastic effect.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.520-524
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• 2008

This research verifies the phenomenon of which the Momentum and Reversal effect of stock price would depend on the subject of investment in the point of view of the Behavior Finance hypothesis. For the experiment, this paper uses the KOSPI200 daily data and Net Investment Flow from Jan. 1999 to Dec. 2006. And we analyze the marginal profit and loss with foreigners, individual investors, and institutions. We verify the response of the subjects of investment based on the CAR for 3 days after more than 3 percent rising or drop. We also verify the response with respect to the ascending and descending trend based on the profit trend and subjects' behaviors a week before the drop.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.115-120
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• 2010

반응표면실험계획들을 평가하기 위한 방법으로서 전형적인 방법이 알파벳최적화이다. 그러나 이러한 알파벳최적화(D-, A-, G-, V-최적화 등)는 하나의 수치이므로 그 유용성에도 불구하고 반응표면실험 계획들이 갖는 추정반응값분산의 분포에 대한 정보에 한계를 갖는다. 이를 극복하고자 하는 대안으로서 그래픽 방법들이 있는데 우리는 그 중에 분위수그림을 애니메이션화한 동적분위수그림을 제안할 수 있고 이 동적분위수그림을 이용하여 반응표면실험계획들이 갖는 추정반응값분산의 분포를 서로 비교, 평가 할 수 있다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1992.04b
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• pp.117-126
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• 1992

This study proposes a new interactive multicriteria method for determining the best levels of the decision variables needed to optimize a stochastic computer simulation with multiple response variables. The method, called the Pairwise Comparison Stochastic Cutting Plane (PCSCP) method, combines good features from interactive multiple objective mathematical programming methods and response surface methodology. The major characteristics of the PCSCP algorithm are: (1) it interacts progressively with the decision maker (DM) to obtain his preferences, (2) it uses good experimental design to adequately explore the decision space while reducing the burden on the DM, and (3) it uses the preference information provided by the DM and the sampling error in the responses to reduce the decision space. This paper presents the basic concepts of the PCSCP method along with its performance for solving randomly selected test problems.

• Journal of Korean Society for Quality Management
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• v.25 no.1
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• pp.56-68
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• 1997

The object of multiresponse optimization is to determine conditions on hte independent variables that lead to optimal or nearly optimal values of the response variables. Derringer and Suich (1980) extended Harrington's (1965) procedure by introducing more general transformations of the response into desirability functions. The core of the desirability a, pp.oach condenses a multivariate optimization into a univariate one. But because of the subjective nature of this a, pp.oach, inexperience on the part of the user in assessing a product's desirability value may lead to inaccurate results. To compensate for this defect, a weighted desirability function is introduced which takes into consideration the vriances of the responses.

• The Korean Journal of Financial Management
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• v.26 no.1
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• pp.127-163
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• 2009

This paper examines the results of survey that the foreign ownership is cointegrated with capital market conditions in Korea using Vector Error Correction Model (VECM) and how the mechanism of innovations and dynamics among the foreign ownership and capital market proxies in the VECM was described. Specifically, we find that the foreign ownership and capital market proxies follow I (1) process and there are cointegrated relations between the foreign ownership and capital market proxies. Adopting the impulse response function and variance decomposition in the VECM, we suggest, in turn, the default risk premia, liquidity of market and the rate of interest in long term business cycle take on a special function on the KSE and KOSDAQ. Finally, we also offer evidences of which there are differences of the mechanism of dynamics and innovations between on the KSE and on the KOSDAQ.

• Journal of Korea Society of Digital Industry and Information Management
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• v.13 no.3
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• pp.35-42
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• 2017

This paper presents hardware implementation of background timing-skew calibration technique for time-interleaved analog-to-digital converters (TI ADCs). The timing skew between any two adjacent analog-digital (A/D) channels is detected by using pure digital Finite Impulse Response (FIR) delay filter. This paper includes hardware architecture of the system, main units and small sub-blocks along with control logic circuits. Moreover, timing diagrams of logic simulations using ModelSim are provided and discussed for further understanding about simulations. Simulation process in MATLAB and Verilog is also included and provided with basic settings need to be done. For hardware implementation it not practical to work with all samples. Hence, the simulation is conducted on 512 TI ADC output samples which are stored in the buffer simultaneously and the correction arithmetic is done on those samples according to the time skew algorithm. Through the simulated results, we verified the implemented hardware is working well.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.3
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• pp.27-36
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• 1998

This work has improved the method of Kim and Gal's (6) in that of requiring less response of the DM(decision maker) and ease of reply. The underlying notion is the MCDC(maximally changeable dominance cone) for describing all efficient solutions under the particular preference structure. According to the DM's partial preference expression, enlarging the MCDC is achieved, which results in reducing the solutions needed to take into consideration. The cone generators corresponding to the DM's response are added to the MCDC, which results the MCDC is enlarged. Adopting the scheme of pairwise comparison as a means of acquiring preference attitude, an improved interactive method is proposed. And also, a scheme of choosing a reference point is suggested to achieve the computational efficiency.

• Journal of Korean Society for Quality Management
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• v.29 no.1
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• pp.24-40
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• 2001

Response surface designs can be classified, according to the shape of the experimental region, into spherical designs and cuboidal designs. Among the central composite design(CCD)s and the Box-Behnken design(BBD)s that are popular in practice, when the number of factors is k, spherical designs are tile CCDs with the axial value being $\sqrt{\textit{k}}$ and the BBDs, and cuboidal designs are the CCDs with the axial value being 1. With the CCDs having $\sqrt{\textit{k}}$ as the axial value, the radius of the experimental region varies with number of factors, but these designs are the 5-level designs. With the BBDs that are 3-level designs, the radius of the experimental region does not vary with the number of factors. In this article, we propose tile 3-level spherical designs which are constructed so that tile radius of the experimental region varies with the number of factors.