• Journal of the Korean Statistical Society
• /
• v.15 no.1
• /
• pp.31-45
• /
• 1986

It is often necessary to obtain some run orders in factorial designs which have a small number of factor level changes and a small linear time trend. In this paper we propose an algorithm to find optimal or near-optimal run orders for $2^4, 2^5, 3^2$ and $2\cdot 3^2$ factorial designs under the criterion that the number of factor level changes and the linear time trend should be simultaneously small.

• Journal of the Korean Statistical Society
• /
• v.5 no.2
• /
• pp.101-107
• /
• 1976

One of the important properties of a 'good' response surface design is that the design should be insensitive to wild observations. In this note, a measure of sensitivity to wild observations is studied. It is shown that designs are made robust to wild observations by making $Tr[X'X)^{-1}M]$ small where M is a moment matrix over some region of interest. The proposed criterion is compared with that suggested by Box and Draper. Some about robust two-variable response surface designs are given.

• Journal of Fashion Business
• /
• v.13 no.6
• /
• pp.89-98
• /
• 2009

Computer development and new printing technology allow us to express a new type of digital textile designs those were not possible in the past. In this study, watercolor overlaying effect of various colors was tried using airbrush tool in Photoshop program. Photoshop program is a powerful graphic tool and can be used in textile design area to generate various types of designs. Woven texture was also applied to the design to give yarn dyed effects or rich appearance. Photoshop program was also used to develop woven texture without the help of the professional textile CAD. Photoshop channels enables the designers to apply various textures to the image. Plain weave and houndstooth were applied in this study. Colorways of the developed designs having watercolor effect and woven texture by applying Photoshop color adjustment function. Quick and simultaneous changes of colors were possible using this method. The developed textile designs were printed by transfer DTP. Successful textile design prints were expressed and showed watercolor overlaying effect and woven texture. The printed textiles show a little brighter color, and therefore, sample printing is recommendable in case of color sensitive production.

• Architectural research
• /
• v.18 no.1
• /
• pp.31-38
• /
• 2016

The surface design in architecture plays a role as an indicator that symbolizes cultures and styles, in accordance with the course of history and the standards of the time. The surface design that determines the facade of an architectural structure allows us to have a more clear understanding about the functions, programs and structures, as well as the periodical concept of the architects than any other components of the architecture. The purpose of this paper was to examine how architectural surface designs were realized, using commonly-used materials. This study provides meaningful implications, in that it suggests common features in terms of design methodologies (between architecture and non-architecture fields), and presented new possibilities for contemporary architectural surface designs through the classification of building system methods depending on fabric properties, and through the case study analysis of architectural surface designs; in addition, the results of this study could be utilized as basic data for future studies on the possibility of the expression of surface designs across a broader domain.

• Korean Journal of Biological Psychiatry
• /
• v.19 no.4
• /
• pp.159-163
• /
• 2012

An appropriate research design for hypotheses and purposes leads to a good quality of research results. In this review article, we summarized the types of research methods and described the characteristics of clinical trials. Research designs are categorized into observational studies and experimental ones, depending on data collecting methods. In an observational study, there are cross-sectional, cohort and case-control studies. Parallel groups design and crossover trial studies are representative designs in a randomized controlled trial study, a kind of experimental study. Clinical researchers should understand the characteristics of clinical research designs including advantages and disadvantages and choose the suitable design according to their study purposes and the nature of collected data or subjects.

• Journal of Korean Society for Quality Management
• /
• v.14 no.1
• /
• pp.26-32
• /
• 1986

A class of multi-factor designs for estimating the slope of second order response surfaces is presented. For multi-factor designs the variance of the estimated slope at a point is a function of the direction of measurement of the slope and the design. If we average the variance over all possible directions, the averaged variance is only a function of the point and the design. By choice of design, it is possible to make this variance constant for all points equidistant from the design origin. This property is called "slope-rotatability over all directions", and the necessary and sufficient conditions for a design to have this property are given and proved. The class of design with this property is mainly discussed.

• The Korean Journal of Applied Statistics
• /
• v.10 no.1
• /
• pp.61-68
• /
• 1997

In this paper, we show that the proper equi-replicate binary designs with h($h\geq2$)-concurrence most balanced designs are (M, S)-optimal. It is very difficult to construct with more than 3-concurrence designs, so we choose 3-concurrence most balanced designs out of the known PBIBD(3).

• Communications for Statistical Applications and Methods
• /
• v.26 no.6
• /
• pp.527-538
• /
• 2019

This paper considers the issue of obtaining the optimal design in Poisson regression model when the sample size is small. Poisson regression model is widely used for the analysis of count data. Asymptotic theory provides the basis for making inference on the parameters in this model. However, for small size experiments, asymptotic approximations, such as unbiasedness, may not be valid. Therefore, first, we employ the second order expansion of the bias of the maximum likelihood estimator (MLE) and derive the mean square error (MSE) of MLE to measure the quality of an estimator. We then define DM-optimality criterion, which is based on a function of the MSE. This criterion is applied to obtain locally optimal designs for small size experiments. The effect of sample size on the obtained designs are shown. We also obtain locally DM-optimal designs for some special cases of the model.

• Journal of Korean Society for Quality Management
• /
• v.40 no.1
• /
• pp.15-24
• /
• 2012

For the construction of fractional factorial designs, the various arrays can be widely used. In this paper we review the statistical properties of fractional designs constructed by two arrays such as orthogonal array and partially balanced array, and develop a quick and easy method for analyzing unreplicated saturated designs. The proposed method can be characterized that we control the error rate by experiment-wise way and exploit the multivariate Student $t$-distribution. Especially the proposed method can be used efficiently together with some exploratory analysis methods, such as half normal probability plot method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.369-370
• /
• 2008

This paper describes the electric field distribution of high voltage polymer bushing with inner field shaper designs. The field control can be achieved by means of the designs of such internal field shaper. But high electric stress occurred between field shaper and central conductor by the closely space. In accordance, the floating and ring shield designs was importance for electric stress grading at critical parts of the bushing. The bushing has a central conductor, and internal ring shield or floating shield, gaps are formed between field shaper and ring shield. Accordance equipotential lines extend through gaps. Maxwell 2D simulator based on the boundary element method was also introduced in order to verify the reliability of the polymer bushing.