• Journal of the Korean Statistical Society
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• 제36권4호
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• pp.557-578
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• 2007

In Response Surface Methodology (RSM), rotatability is a natural and highly desirable property. For second order general correlated regression model, the concept of robust rotatability was introduced by Das (1997). In this paper a new measure of robust rotatability for second order response surface designs with correlated errors is developed and illustrated with an example. A comparison is made between the newly developed measure with the previously suggested measure by Das (1999).

• Journal of the Korean Statistical Society
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• 제32권4호
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• pp.337-357
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• 2003

This paper introduces new measures for the stability of slope estimation on the second order response surface at a point and on a sphere. As a measure of point stability of slope estimation, we suggest a point dispersion measure of slope variances over all directions at a point. A spherical dispersion measure is also proposed as a measure of spherical stability of slope estimation on each sphere. Some designs are studied to explore the usefulness of the proposed measures. Using the point dispersion measure, another concept of slope rotatability called equally-stable slope rotatability is proposed as a useful property of response surface designs. We provide a set of conditions for a design to have equally-stable slope rotatability.

• Communications for Statistical Applications and Methods
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• 제30권1호
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• pp.49-63
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• 2023

A lot of studies on the summary measures of predictive strength of categorical response models consider the likelihood ratio index (LRI), also known as the McFadden-R², a better option than many other measures. We propose a simple modification of the LRI that adjusts for the effect of the number of response categories on the measure and that also rescales its values, mimicking an underlying latent measure. The modified measure is applicable to both binary and ordinal response models fitted by maximum likelihood. Results from simulation studies and a real data example on the olfactory perception of boar taint show that the proposed measure outperforms most of the widely used goodness-of-fit measures for binary and ordinal models. The proposed R² interestingly proves quite invariant to an increasing number of response categories of an ordinal model.

• Communications for Statistical Applications and Methods
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• 제11권3호
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• pp.563-574
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• 2004

Slope rotatability of response surface designs is a desirable property when we are interested in estimating slopes of response surfaces. In this paper, we derive a simplified measure of slope rotatability from new viewpoints for response surface designs that are frequently used in response surface methodology.

• 품질경영학회지
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• 제27권1호
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• pp.59-79
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• 1999

The fitting of a response surface model and the subsequent exploration of the response surface are usually based on the assumption that the experimental runs are carried out under homogeneous conditions. This, however, may be quite often difficult to achieve in many experiments. To control such an extraneous source of variation, the response surface design should be arranged in several blocks within which homogeneity of conditions can be maintained. In this case, when fitting a response surface model, the least squares estimates of the model's parameters and the prediction variance will generally depend on how the response surface design is blocked. That is, the choice of a blocking arrangement for a response surface design can have a considerable effect on estimating the mean response and on the size of the prediction variance. In this paper, we propose a measure for evaluating the effect of blocking of response surface designs using cuboidal regions.

• Communications for Statistical Applications and Methods
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• 제7권2호
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• pp.415-426
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• 2000

Hader and Park (1978) introduced the idea of slope rotatability, and Park (1987) introduced the concept of slope rotatability over all directions, and gave necessary and sufficient conditions. Park and Kim (1992) proposed a measure that represent the extent of slope rotatability for a given response surface design. Kim (1993) proposed a measure that represent the extent of slope rotatavility over all directions. In this paper, we embodied the measure of slope rotatability over all directions. Examples of applying this measure to some response surface designs are also given. In this response surface design of slope rotatavility over all directions, we obtain the mean slope variances on the spherical surface to select better experimental design varying the number of center points and radius.

• International Journal of Human Ecology
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• 제5권2호
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• pp.13-29
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• 2004

Ryff's(1989) psychological well-being measure is used to assess and sometimes compare Korean and American adults, however, there is no information regarding whether its dimensions are psychometrically invariant across, whether its items provide sufficient information for, and whether each item measures identical trait levels in, the two nations. Confirmatory factor analysis on response 1,696 Korean and 3,669 American adults, gave to the measure revealed lack of fit and absence of factorial invariance across the two nations. Item response theory revealed significant variance for items on each factor across two countries that most items yielded limited psychometric information. And that each item measure different trait levels, suggesting that in its present form, the measure might lead to misleading results for, and across the two nations.

• 대한산업공학회지
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• 제8권1호
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• pp.13-21
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• 1982

Experiments on the eye movement behavior were performed using Vidicon Eye Camera. Factorial design ( $3{\times}3$) was used to evaluate the validity of the eye movement as a performance measure in vigilance task. Eye movement data were recorded in video tapes, then the data were converted to digital signals, which were reduced to quantitative fixation and saccadic movement data by a microcomputer. To compare with existing vigilance performance measures, response time and the number of false alarms were also recorded. The results showed that the saccadic movement is a good measure of the performance in vigilance task : 1. Both the response time and the saccadic movement increased significantly during the initial two time blocks. 2. High correlations were shown between the response time and the saccadic movement. 3. The locational uncertainty affects the saccadic movement, the number of fixations, the response time but doesn't affect the duration of eye fixations.

• Journal of Preventive Medicine and Public Health
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• 제48권6호
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• pp.277-279
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• 2015

Contact monitoring is an essential component of the public health response to a Middle East respiratory syndrome coronavirus outbreak, and is required for an effective quarantine to contain the epidemic. The timeliness of a quarantine is associated with its effectiveness. This paper provides a conceptual framework to describe the process of contact monitoring, and proposes a new measure called the "timely quarantined proportion" as a tool to assess the adequacy of a public health response.

• 대한감각통합치료학회지
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• 제9권1호
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• pp.45-52
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• 2011

목적 : 성인 정신장애를 대상으로 청각자극에 대한 생리학적 반응을 측정한 연구에서 사용된 청각자극의 종류와 측정도구를 알아보고 대상군의 자율신경계 반응특성을 제시하고자 한다. 연구방법 : 연구방법으로는 체계적 고찰을 사용하였다. 사용한 데이터베이스는 PubMed이었다. 검색어는 "auditory stimulation, auditory startle, electromyogram, skin conductance, heart rate, psychiatric disorder, anxiety disorder, schizophrenia, depression"이었다. 최종적으로 분석에 사용된 논문은 8개이었으며, 근거의 질적 수준은 모두 수준II이었다. 분석 내용은 대상군의 특성, 청각자극의 종류, 측정도구, 정신 장애의 청각자극에 대한 생리학적 반응특성이었다. 결과 : 1. 연구 대상군은 불안장애와 정신분열장애를 대상으로 한 연구가 각각 4개이었다. 2. 생리학적 반응 유발을 위해 청각자극만 제공한 연구가 6개, 청각자극과 함께 시각자극을 포함한 연구가 2개이었다. 3. 분석대상 연구 모두에서 근전도(electromyograph)를 사용하였으며, 근전도와 함께 피부전기전도(skin conductance)를 측정한 연구가 2개, 심박수(heart rate)를 측정한 연구가 2개이었다. 4. 정신분열장애와 불안장애(외상후 스트레스장애, 강박장애)는 일반인과 다른 생리학적 반응을 보였다. 결론 : 생리학적 반응을 측정하기 위한 연구에서 사용한 자극은 청각자극으로 단순음을 제시하였고, 근전도는 안륜근에 전극을 붙여 생리학적 반응을 측정하였다. 정신장애군은 청각자극에 대해 큰 반응, 짧은 잠재기, 지연된 습관화 등의 특징을 보였다. 앞으로 정신장애군의 감각 특성에 대하여 생리학적 측정을 통한 연구가 이루어져야 하겠다.