• 동력기계공학회지
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• 제18권1호
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• pp.22-31
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• 2014

This paper introduced the new calibration algorithm of a straight-type five-hole pressure probe necessary for calculating three-dimensional flow velocity components. The new velocity data reduction method using both a commercial two-dimensional curve-fitting program and the zone partition method of a calibration map was firstly introduced in this study. This new calibration method can be applied up to the wide flow angle of ${\pm}80^{\circ}$ despite of using a five-hole pressure probe because this data reduction method showed a comparatively good performance in calculating yaw and pitch angles from the calibration map.

• 대한수학회논문집
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• 제34권3호
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• pp.1029-1047
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• 2019

We are interested in the problem of determining the best fitted circle to a set of data points in space. This can be usually obtained by minimizing the geometric distances or various approximate algebraic distances from the fitted circle to the given data points. In this paper, we propose an algorithm in such a way that the sum of the squares of the geometric distances is minimized in ${\mathbb{R}}^3$. Our algorithm is mainly based on the steepest descent method with a view of ensuring the convergence of the corresponding objective function Q(u) to a local minimum. Numerical examples are given.

• 대한안전경영과학회지
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• 제12권4호
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• pp.87-92
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• 2010

The mask-face interface design should consider the face shape to improve the half mask respirator's fit ratio. This study tried to design the mask-face interface using recent Korean face data. By using the data of 1536 men's 3D face scanning (Size Korea data), head clay mock-up was made and mask-face interface line was extracted from this head mock-up. Using this interface line, the half-mask prototype was made. According to the quantitative fitting test, the proposed mask was found to be well fitted (average fit-ratio > 100). The proposed method had two advantages. 1) The method could use massive head-related anthropometric data like Size Korea data. 2) The qualitative fit test (observation) could be conducted very quickly by fitting the prototype to the head mock-up. However, this method also had several limitations. 1) The head clay mock-up could be different according to the mock-up maker. 2) The average values of the head-related anthropometric data were used to make the head mock-up. Small and large size head mock-ups should be made and tested.

• 센서학회지
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• 제31권4호
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• pp.260-265
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• 2022

In this study, we establish hyper-elastic haptic feedback in a virtual environment using finite element analysis techniques and develop a Force Torque (FT) sensor utilization method for application in tele-operation environments. In general, regarding haptic feedback data, in a tele-operation environment, the user is provided with feedback according to the measured force data when the model is inserted through an FT sensor. Conversely, in a virtual environment, the press-fitting model can be expressed through the spring-damper system rather than an FT sensor to provide feedback. However, unlike rigid and the elastic bodies, the hyper-elastic body represented by a spring-damper system in a virtual environment is a simple impedance model using stiffness and damping coefficients; it is limited in terms of providing actual feedback. Thus, in this study, haptic feedback was implemented using the data obtained from POD-RBF analysis results during hyper-elastic press-fitting experiments. The haptic feedback mechanism developed in this study was verified by comparing the FT sensor feedback data measured and calculated through hyper-elastic press-fitting experiments with spring-damper feedback data. Subsequently, the POD-RBF analysis feedback was compared and evaluated against the feedback mechanism of each environment through the test subject, and the similarities between the POD-RBF analysis feedback and FT sensor data feedback were verified.

• 한국의류학회지
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• 제27권7호
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• pp.735-745
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• 2003

This paper looks at perceived images of female university students concerned with various wedding hair coordination including wedding hair styles, veil details and fitting positions and head dresses. Ta design an experimental test of a wedding dress and hair coordination variables, the content analysis of magazines was performed and hair experts were interviewed. 17 stimuli representing the variables of wedding hair coordination were manipulated and included with hair styles(2), veil details(2), veil fitting Positions(2), head dresses(2) and a wedding hat(1). The questionnaire of 445 was carried out and data were statistically processed. As a result, five images of wedding hair coordination were factors loaded, that is, favorable, decorative, smooth, personal and pretty one. Various main and interaction effects were found in images of it regarding to changing hair styles, different veil details and fitting positions and head dresses. favorable images, they affected by interactions between hair styles and veil details, hair styles and veil fitting positions, hair styles and head dresses and between veil details and the fitting positions. For personal images, interactions between veil details and the positions of veil fitting had effects on female students; for smooth images, That is, for hair style, female university students were influenced by favorable and smooth images; for veil details, by decorative and smooth images; for the positions of fitting veil, by decorative and favorable ones Then the researcher examined effects by dual interactions between factors of wedding hair coordination. For decorative images, they were found influenced by interactions between hair styles and veil details and between hair styles and head dresses. For personal ones, interactions between veil details and the fitting positions; for pretty images, interactions between the fitting positions and head dresses. These findings will provide sellers of the wedding dress with the idea of how females to perceive wedding hair coordination according to the variation of it.

• 패션비즈니스
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• 제17권5호
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• pp.57-69
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• 2013

The purpose of this study is to compare the traditional shopping model and virtual avatar fitting model with regards to credibility and favorable impression effects on shopping mall satisfaction, product preferences, and purchasing intentions of apparel e-commerce. Questionnaires are distributed to 10-30s years old consumers who live in Seoul. Data are analyzed by descriptive statistics, Cronbach's ${\alpha}$, and regression analysis. The results are that the provoked credibility and favorable impression from the traditional shopping model affects the consumers' shopping mall satisfaction and buying intention in descending order. In additional, the credibility from traditional shopping model affects the product preference. The provoked credibility from the virtual fitting model influences the consumers' product preferences, and buying intentions. The favorable impression from the virtual fitting model affects shopping mall satisfaction. In general, provoked credibility from virtual avatar fitting model and traditional shopping model play key roles which could influence the consumers' buying intention.

• 한국정보시스템학회지:정보시스템연구
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• 제31권1호
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• pp.25-58
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• 2022

Purpose The purpose of this study is to analyzes the RPA fitting processes by the casese of manufacturing SMEs(Small and Medium-sized Enterprises) in an exploraty approach. Based on the findings on the RPA fitting processes, we intend to provide a cornerstone for developing a general-purpose RPA introduction model in the future. Design/methodology/approach In this study, empirical cases of RPA fitting processes were analyzed based on interviews with project managers of specialized IT suppliers in charge of RPA development and managers of IT departments of manufacturing SMEs that actually introduced RPA. In order to explore various RPA fitting process in the manufacturing value chain, a total of 7 manufacturing SMEs were interviewed, ranging from companies using a legacy system to companies without a legacy system. Over the primary and secondary activity processes, the details of RPA processes were analyzed in the steps of 'Frequency Identification, Input Processing, Source Identification, Inquiry and Processing, Information Registration, Result Reporting'. Findings From the analysis, we derived some exploratory results that the processes over 0.25 FTE and related with many suppliers and clients are fitting for RPA introduction in manufacturing SMEs Our results will provide basic data for the development of the future general-purpose RPA introduction model for manufacturing SMEs, providing practical reference for RPA introduction.

• 한국의상디자인학회지
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• 제15권3호
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• pp.137-156
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• 2013

The purpose of this study is to analyze the general status of wearing clothes and clothing purchase of middle-aged women in the 40's to 50's, the patterns and colors of clothes they prefer, clothing preference related with fitting or such, and also complaints. And this paper also divides the middle-aged women into those in the 40's and 50's to analyze how they differ in terms of the apparel brands and fitting they prefer and also the status of wearing clothes. For the research, a survey was performed to 350 women, and the survey data went through x2 and t-test analysis by using SPSS 20.0 to examine significant difference. The results of this study are as follows: the women in the 40's included as the subjects showed a high frequency of clothing purchase from casual brands or SPA brands and regarded design to be important at the clothing purchase. Meanwhile, the women in the 50's indicated a higher frequency of clothing purchase of middle-aged women's apparel brands, outdoor brands, madam clothes, or designer brands and thought activity to be crucial at the clothing purchase. As the women in the 40's and 50's showed difference in the brands they preferred, particularly the fitting indicated difference in terms of dissatisfaction. While those in the 40's preferring and buying young casual showed particularly more fitting problems in the arm-hole girth, upper arm circumference, bust size, and thigh or hip area, those in the 50's indicated fitting problems in the hip circumference or waist measurement. It is expected that this study will be used as foundational data to set up the target age by related apparel companies or develop clothes with great size fitting and design satisfaction.

• Journal of Computational Design and Engineering
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• 제2권4호
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• pp.218-232
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• 2015

Piecewise linear (G01-based) tool paths generated by CAM systems lack $G_1$ and $G_2$ continuity. The discontinuity causes vibration and unnecessary hesitation during machining. To ensure efficient high-speed machining, a method to improve the continuity of the tool paths is required, such as B-spline fitting that approximates G01 paths with B-spline curves. Conventional B-spline fitting approaches cannot be directly used for tool path B-spline fitting, because they have shortages such as numerical instability, lack of chord error constraint, and lack of assurance of a usable result. Progressive and Iterative Approximation for Least Squares (LSPIA) is an efficient method for data fitting that solves the numerical instability problem. However, it does not consider chord errors and needs more work to ensure ironclad results for commercial applications. In this paper, we use LSPIA method incorporating Energy term (ELSPIA) to avoid the numerical instability, and lower chord errors by using stretching energy term. We implement several algorithm improvements, including (1) an improved technique for initial control point determination over Dominant Point Method, (2) an algorithm that updates foot point parameters as needed, (3) analysis of the degrees of freedom of control points to insert new control points only when needed, (4) chord error refinement using a similar ELSPIA method with the above enhancements. The proposed approach can generate a shape-preserving B-spline curve. Experiments with data analysis and machining tests are presented for verification of quality and efficiency. Comparisons with other known solutions are included to evaluate the worthiness of the proposed solution.

• 한국재료학회지
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• 제29권7호
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• pp.412-424
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• 2019

Global fitting functions for Fe-selective chlorination in ilmenite($FeTiO_2$) and successive chlorination of beneficiated $TiO_2$ are proposed and validated based on a comparison with experimental data collected from the literature. The Fe-selective chlorination reaction is expressed by the unreacted shrinking core model, which covers the diffusion-controlling step of chlorinated Fe gas that escapes through porous materials of beneficiated $TiO_2$ formed by Fe-selective chlorination, and the chemical reaction-controlling step of the surface reaction of unreacted solid ilmenite. The fitting function is applied for both chemical controlling steps of the unreacted shrinking core model. The validation shows that our fitting function is quite effective to fit with experimental data by minimum and maximum values of determination coefficients of $R^2$ as low as 0.9698 and 0.9988, respectively, for operating parameters such as temperature, $Cl_2$ pressure, carbon ratio and particle size that change comprehensively. The global fitting functions proposed in this study are expressed simply as exponential functions of chlorination rate(X) vs. time(t), and each of them are validated by a single equation for various reaction conditions. There is therefore a certain practical merit for the optimal process design and performance analysis for field engineers of chlorination reactions of ilmenite and $TiO_2$.