• Asia Marketing Journal
• /
• v.8 no.1
• /
• pp.1-17
• /
• 2006

A couple of previous studies have warned against the use of homogeneous choice models in assessing the effect of reference price since unaccounted for response heterogeneity may result in spurious reference price effects(Chang, Siddarth and Weinberg 1999; Bell and Lattin 2000). According to Meyer and Kahn(1991), not accounting for consideration set heterogeneity may also bias the effect parameters in the choice model. Therefore, failure to account for these two sources of bias, in fact, have cast doubt on the empirical support for reference price effects in general. In view of aforementioned potential sources of bias, the author investigates the robustness of loss aversion effect in the reference-dependent model after accounting for heterogeneity in response as well as consideration set. The proposed model defines individual household's consideration set based on the posterior distribution of preference obtained from the Empirical Bayes approach. In addition, the same posterior distribution is used to form household-specific reference prices. Response heterogeneity correction is carried out via the Latent Class approach. The proposed model outperforms the Reference-Dependent model that includes the reference price measure most often employed in the previous studies. This implies that as a way of simplifying decision task, consumers restrict their consideration set to a subset of available brands not only in making a brand choice but also in forming reference prices.

• Communications for Statistical Applications and Methods
• /
• v.22 no.6
• /
• pp.655-664
• /
• 2015

A nonresponse adjusted raking ratio estimator that consists of weighting adjustment using estimated response probability and raking procedure is often used to reduce the nonresponse bias and keep the calibration property of the estimator. We investigated asymptotic properties of nonresponse adjusted raking ratio estimator and proposed a variance estimator. A simulation study is used to examine the performance of suggested estimators.

• Journal of the Korean Data and Information Science Society
• /
• v.5 no.2
• /
• pp.107-116
• /
• 1994

이 논문은 통계상담사례연구의 일종으로 설문지를 이용한 통계자료분석에 도움이 되도록 소개하고자 한다. 여러항목을 종합하여 한 척도를 구성하고 각 항목마다 중요도나 선호도 등에 따라 다품등 리커트형 척도를 묻는 자료는 개인의 성향이나 지리적 문화적 여건에 따라 그 응답경향이 달라 가질지도 모르는 반응편향성(Response Set Bias)을 감소시켜 보다 좋은 통계자료분석을 할 수 있는 통계적 방법을 소개하며, 이 방법을 적용시킨 통계상담을 예시하고자 한다.

• Communications for Statistical Applications and Methods
• /
• v.3 no.3
• /
• pp.93-101
• /
• 1996

The unknown response function is usually approximated by a low order polynomial model. Such an approximation always accompanies bias due to model departure. The minimax Average MSE (AMSE) designs are suggested for estimating mean responses. A class of first order minimax AMSE designs is derived and a specific first order minimax AMSE design is selected from the class by optimizing the secondary criterion related to the power of the lack of fit test.

• Journal of the Optical Society of Korea
• /
• v.9 no.4
• /
• pp.131-134
• /
• 2005

We have proposed a method to calculate the absorption coefficients for the bound-to-continuum transitions in a strong biased quantum-well infrared photodetector. We have applied this method to a manufactured sample of typical device parameters, and obtained good agreements with experiments. The absorption coefficients evaluated are up to 5,700/cm at some particular operating conditions. We have also been able to make a qualitative explanation for the bias dependence of response.

• Journal of the Ergonomics Society of Korea
• /
• v.31 no.2
• /
• pp.413-419
• /
• 2012

Objective: This study presents an observation and analysis on behavioral characteristics of old users in comparison to young users in the use of control on display interface. Background: Touch interface which allows users to control directly on display, is conceived as delight and easy way of human-computer interaction. Due to the advantage in stimulus-response ensemble, the old users, who typically experiencing difficulties in interacting with computer, would expected to have better experience in using computing machines. Method: Twenty nine participants who are over 50 years old and 14 participants who are in 20s years old were participated in this study. Three primary tasks in touch interface, which are tap, move, and flick, were delivered by the users. For the tap task, response time and point of touch response were collected and the response bias was calculated for each trial. For the move task, delivery time and the distance of finger movements were recorded for each trial. For the flick task, task completion time and flicking distance were recorded. Results: From the collected behavioral data, temporal and spatial differences between young and old users behavior were analyzed. The older users showed difficulty in completing move task requiring eye-hand coordination.

• Communications for Statistical Applications and Methods
• /
• v.17 no.6
• /
• pp.899-907
• /
• 2010

Several non-response imputation methods are suggested, however, mainly cross-sectional imputations are studied and applied to this analysis. A simple and common imputation method for panel data is the cross-wave regression imputation or carry-over imputation as a special case of cross-wave regression imputation. This study suggests a multiple imputation method combined time series analysis and cross-sectional multiple imputation method. We compare this method and the cross-wave regression imputation method using MSE, MAE, and Bias. The 2008 monthly labor survey data is used for this study.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.25 no.6
• /
• pp.233-240
• /
• 2021

The stochastic method is applied to simulate strong ground motions at seismic stations of seven metropolises in South Korea, creating an earthquake scenario based on the causative fault of the 2016 Gyeongju earthquake. Input parameters are established according to what has been revealed so far for the causative fault of the Gyeongju earthquake, while the ratio of differences in response spectra between observed and simulated strong ground motions is assumed to be an adjustment factor. The calculations confirm the applicability and reproducibility of strong ground motion simulations based on the relatively small bias in response spectra between observed and simulated strong ground motions. Based on this result, strong ground motions by a scenario earthquake on the causative fault of the Gyeongju earthquake with moment magnitude 6.5 are simulated, assuming that the ratios of its fault length to width are 2:1, 3:1, and 4:1. The results are similar to those of the empirical Green's function method. Although actual site response factors of seismic stations should be supplemented later, the simulated strong ground motions can be used as input data for developing ground motion prediction equations and input data for calculating the design response spectra of major facilities in South Korea.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.14 no.6
• /
• pp.236-243
• /
• 2004

The oxide etching process was characterized in a magnetically enhanced reactive ion etching (MERIE) reactor with a $CHF_3CF_4$ gas chemistry. A statistical experimental design plus one center point was used to characterize relationships between process factors and etch response. The etch response modeled are etch rate, etch selectivity to TiN and uniformity. Etching uniformity was improved with increasing $CF_4$ flow ratio, increasing source power, and increasing pressure depending on source power. Characterization of via etching in $CHF_3CF_4$ MERIE using neural networks was successfully executed giving to highly valuable information about etching mechanism and optimum etching condition. It was found that etching uniformity was closely related to surface polymerization, DC bias, TiN and uniformity.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.970-973
• /
• 2003

Abstract An idea to redce the direct-path short circuit current of the CMOS digital integrated circuit is present. The sample circuit model of the CMOS digital circuit is the CMOS current-control digital output driver circuit, which are also suitable for the low voltage supply integrated circuits as the simple digital inverter, are present in this title. The circuit consists of active MOS load as the current control source, which construct from the saturated n-channel and p-channel MOSFET and the general CMOS inverter circuits. The saturated MOSFET bias can control the output current and the frequency response of the circuit. The experimental results show that lower short circuit current control can make the lower frequency response of the circuit.