• International Journal of Aeronautical and Space Sciences
• /
• 제2권2호
• /
• pp.73-81
• /
• 2001

This paper describes the procedure to develop a robust estimator design method for a target tracker that accounts for both structured real parameter uncertainties and unknown inputs. Two robust design approaches are combined: the Mini-p-Norm. design method to consider real parameter uncertainties and the $H_{\infty}$ design technique for unknown disturbances and unknown inputs. Constant estimator gains are computed that guarantee the robust performance of the estimator in the presence of parameter variations in the target model and unknown inputs to the target. The new estimator has two design parameters. One design parameter allows the trade off between small estimator error variance and low sensitivity to unknown parameter variations. Another design parameter allows the trade off between the robustness to real parameter variations and the robustness to unknown inputs. This robust estimator design method was applied to the longitudinal motion tracking problem of a T-38 aircraft.

• 패션비즈니스
• /
• 제23권3호
• /
• pp.1-9
• /
• 2019

The purpose of this study was to develop questions for fashion design development, by applying 7 elements of the scamper to the fashion design elements, and to present a scamper checklist of fashion design elements, and item structures. In this study, the scope of research was limited to clothing design among various fashion products, and among various design development stages. Fashion design development focusing on design sketching, was limited to the research scope. The research method was based on an empirical study that derived scamper questions through FGI (Focus Group Interview), consisting of 5 fashion experts. Fashion design elements applied to development of scamper questions consisted of silhouettes, constructive lines, structural details, decorative details, patterns and textures of fabrics, and item structures, derived by applying these elements to the individual 7 elements of the scamper: substitute, combine, adjust, modify, put to other uses, eliminate, and reverse. Results of the study included 7 questions for substituting, 8 questions for combining, 6 questions for applying, 15 questions for modifying, 4 questions for putting to other uses, 4 questions for eliminating, and 7 questions for reversal. The scamper checklist for fashion design elements and item structures drew to 5 lists of silhouette variations, 7 lists of constructive line variations, 11 lists of structural detail variations, 10 lists of decorative detail variations, 11 lists of fabric variations, and 9 lists of structural modifications of items.

• 한국의상디자인학회지
• /
• 제14권2호
• /
• pp.101-111
• /
• 2012

The purpose of this study is to evaluate the differences of visual image on variations in the length and princess line, in a silhouette of a one-piece dress with the application of the 3D Virtual Clothing System known as i-designer. Eight sample were examined: 2 variations of the length and 2 variations of the princess line, 2 variations of the form of a silhouette. The data was obtained from 66 fashion design majors. The data was assessed by a t-test and a multi-way ANOVA and factor analysis. The results were as follows; The visual image according to the design variables, four factors were selected; the attractiveness factor, the activeness factor, the practicality factor, the elegance factor. In these factors, the attractiveness factor is estimated by the most important factor. As a result of analyzing the effect of the interaction in the visual image according to the design variables, the influence of the main effect was found to be great in each factor. In the activeness factor, a significant difference was noted in the two-way interaction between the length and the princess line, the length and the silhouette. In the elegance factor, a significant difference was noted in the two-way interaction between the length and the silhouette. However, the influence on three-way interaction among the length, the princess line, and the silhouette was not significant.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1249-1252
• /
• 2003

To analyse the cyclic variations in a test engine, the burn parameters are determined on a cycle-to-cycle basis through the analysis of the engine pressure data. Combustion analysis based on cylinder-pressure provides a mechanism through which a combustion researcher can understand the combustion process. The objective of this paper is to identify the most significant sources of cycle-to-cycle combustion variability in a spark ignition engine at idle. The burn rate analysis program was used and the burn parameters were used to determine the variations in the input parameter. In this study, the author investigated the relationship of indicated mean effective pressure, coefficient of variation of indicated mean effective pressure and burn angles, and lowest normalized value in a spark ignition engine for the cyclic variations.

• 한국의류산업학회지
• /
• 제7권1호
• /
• pp.63-69
• /
• 2005

The purpose of this study is to evaluate the differences of visual effects by variations in the location of the waistline and the width of the round belt of the basic skirt. The stimuli are 21 samples: 7 variations of the location of the waistline and 3 variations of the width of the belt. The data has been obtained from 43 fashion design majors. The data has analyzed by frequency, factor analysis, anova, scheffe's test and the MCA method. The results of this study are as follows. The visual effects by variations of the location of the waistline and the width of the belt are composed of 3 factors: the shape of the front part of the abdomen, the shape of the side part of the abdomen, and the length of the upper body. The visual effects by variations of the width of the belt have partial significant differences. The visual effects by variations in the location of the waistline have significant differences in all factors. The interaction effects between the location of the waistline and the width of the belt have not significant differences in all factors.

• 패션비즈니스
• /
• 제9권4호
• /
• pp.16-29
• /
• 2005

The purpose of this study is to evaluate the differences of visual image by variations in the location of the waistline and width of the belt of the basic skirt. The stimuli are 21 samples: 7 variations of the location of the waistline and 3 variations of the width of the belt. The data has been obtained from 43 fashion design majors. The data has analyzed by frequency, factor analysis, anova, scheffe's test and the MCA method. The results of this study are as follows. The visual image by variations of the location of the waistline and width of the belt is composed of 3 factors: attention, function, attraction. The visual image by variations of the width of the belt has partial significant differences. The visual image by variations in the location of the waistline has significant differences in all factors. Function shows the interaction between the location of the waistline and width of the belt. However, attention and attraction don't show the interaction between the location of the waistline and width of the belt ; the location of the waistline tends to be the main effect.

• 제어로봇시스템학회논문지
• /
• 제4권6호
• /
• pp.729-737
• /
• 1998

In this paper, using $\mu$ synthesis algorithm with structured uncertainty, we design controller and apply it for the Two-Inertia resonance(TMS: Two Mass Spring) system. The TMS system is one of the simplest models which generate a torsional vibration. In this system, it is required to design a controller achieving the control performance while suppressing the torsional vibration. Furthermore, when vibration frequency for the system is varying by reason of parameter variations, we should consider parameter variations in controller design. Then, we design two other controller schemes of the PI controller and the standard $H_{\infty}$ controller and compare these controllers with the controller designed by the $\mu$ synthesis robust control method by using simulations and experiments.

• 품질경영학회지
• /
• 제43권4호
• /
• pp.589-606
• /
• 2015

Purpose: In developing new products, reducing performance variation is important for competitiveness factors such as quality, cost, and delivery. This paper aims at evaluating three performance variations; measurement, performance evaluation, and manufacturing variations, and then improving product and process design, focused on paper helicopter making case study. Methods: For measurement system analysis, gage R&R (repeatability and reproducibility), linearity, stability are evaluated. Since gage R&R are not satisfactory, the measurement system is improved by adopting voice memos application of iPhone and providing standard measurement procedure. To evaluate performance variation, product deterioration and environment factor (wind speed) is considered. Since the existing design is sensitive to these noise factors, a new product design is developed, which is proven to be robust to the noise factors. Finally, manufacturing variations are evaluated with five factors which can cause variation in flight time. To reduce the impact of three significant factors, three improvement methods are applied. Results: Three performance variations are evaluated and robust paper helicopter design is presented. Conclusion: To reduce measurement and process variations, improved measurement method and paper helicopter making procedure are proposed. A new product design is also presented which is robust to deterioration and environmental variation. This paper is expected to benefit students and practitioners who want to have hands-on knowledge on new product quality improvement.

• 한국CDE학회논문집
• /
• 제10권4호
• /
• pp.284-292
• /
• 2005

This paper presents a new framework of kinematic tolerance synthesis and describes the implemented algorithm for planar mechanical systems comprised of higher kinematic pairs. Input to the synthesis algorithm is a parametric model of the mechanical system with allowed parameter ranges (tolerance ranges). The model is specified as the part profiles consisting of line and arc segments and the motion axes along which each part moves. The algorithm analyzes tolerance in generalized configuration space, called contact zones bounding the worst-case variations, and identifies bad system variations. The bad system variations then are removed out of the parameter ranges by adjusting the nominal parameter values if possible and then shrinking the ranges otherwise. This cycle is repeated until no more bad variations we found. I show the effectiveness of the algorithm by case studies on several mechanisms.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 2001년도 추계학술대회 논문집
• /
• pp.91-95
• /
• 2001

In this study, we estimated the behavior of the diversity of physiological responses under varied physical environmental factors by measuring variations of heart rate variability (HRV), an index of activity of cardiac autonomic control. Seven healthy young male adults consented and participated in the study. The environmental conditions consisted of thermal, lighting, and acoustic conditions. Two components of HRV were measured. one was the low frequency (LF) component of HRV, which provided a quantitative index of the sympathetic and parasympathetic (vagal) activities controlling the heart rate (HR). The other component measured was the high frequency (HF) component, which provided an index of the vagal tone. The percent contribution of physical environmental factors to the variations in HRV indices were calculated by ANOVA. The contribution of physical environmental factors to the variations in HR was higher than the contribution of HF and LF. However, the contribution of these factors was lower than the contribution related with individual difference in all indices. This result showed that the individual diversity of physiological responses is not a negligible quantity.