• Steel and Composite Structures
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• 제42권1호
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• pp.123-137
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• 2022

The fundamental period (FP) is one of the most critical parameters for the seismic design of structures. In the reinforced concrete (RC) infilled frame, the infill walls significantly affect the FP because they change the stiffness and mass of the structure. Although several formulas have been proposed for estimating the FP of the RC infilled frame, they are often associated with high bias and variance. In this study, an efficient soft computing model, namely the group method of data handling (GMDH), is proposed to predict the FP of regular RC infilled frames. For this purpose, 4026 data sets are obtained from the open literature, and the quality of the database is examined and evaluated in detail. Based on the cleaning database, several GMDH models are constructed and the best prediction model, which considers the height of the building, the span length, the opening percentage, and the infill wall stiffness as the input variables for predicting the FP of regular RC infilled frames, is chosen. The performance of the proposed GMDH model is further underscored through comparison of its FP predictions with those of existing design codes and empirical models. The accuracy of the proposed GMDH model is proven to be superior to others. Finally, explicit formulas and a graphical user-friendly interface (GUI) tool are developed to apply the GMDH model for practical use. They can provide a rapid prediction and design for the FP of regular RC infilled frames.

• Advances in Computational Design
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• 제8권2호
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• pp.147-177
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• 2023

Elliptical concrete-filled steel tubular (CFST) column is widely used in modern structures for both aesthetical appeal and structural performance benefits. The ultimate axial load is a critical factor for designing the elliptical CFST short columns. However, there are complications of geometric and material interactions, which make a difficulty in determining a simple model for predicting the ultimate axial load of elliptical CFST short columns. This study aims to propose an efficient adaptive neuro-fuzzy inference system (ANFIS) model for predicting the ultimate axial load of elliptical CFST short columns. In the proposed method, the ANFIS model is used to establish a relationship between the ultimate axial load and geometric and material properties of elliptical CFST short columns. Accordingly, a total of 188 experimental and simulation datasets of elliptical CFST short columns are used to develop the ANFIS models. The performance of the proposed ANFIS model is compared with that of existing design formulas. The results show that the proposed ANFIS model is more accurate than existing empirical and theoretical formulas. Finally, an explicit formula and a Graphical User Interface (GUI) tool are developed to apply the proposed ANFIS model for practical use.

• 패션비즈니스
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• 제27권3호
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• pp.96-114
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• 2023

In modern society, there is a tendency to prioritize both fashion and comfort, with a preference for loose-fit clothing that enhances mobility. While darts may not be visibly present on the garment's exterior, their effects should be dispersed and incorporated into the design. However, there is a significant lack of systematic research on dartless patterns in the current state. Therefore, this study focuses on investigating dartless patterns used in loose-fit clothing tailored to the body measurements of women in their 20s. The objective of this research is to develop foundational dartless patterns that serve as a basis for diverse design possibilities in loose-fit clothing. To achieve this purpose, seven dartless patterns introduced in clothing construction references were selected for the production of experimental prototypes, which were then subjected to visual evaluations by a panel of experts. Based on the evaluation results, superior patterns were selected and they underwent modification and improvement to develop the research patterns. The developed research patterns were derived through the formulation of calculation formulas, and based on these formulas, garments were produced. Subsequently, a second round of visual evaluations was conducted by a panel of experts, and notable improvements were observed in most of the aspects assessed. However, it should be noted that this study was limited to women in their 20s it did not explore a wide range of fabrics. Therefore, further research is needed in the future.

• 대한기계학회논문집
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• 제10권3호
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• pp.419-426
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• 1986

본 연구에서는 가공삭도의 선로설계에 최적화기법을 도입하여 시행착오법보다 신속.정확하면서도 경제성이나 승차감등이 항상된 설계를 위한 절차를 개발하고자 한 다. 이를 위하여 먼저 본 논문에서는 설계에 적용될 선로의 기본이론들을 정리, 혹 은 유도 하였다. 특히 기존의 포물곡선이론의 정확성을 규명하기 위하여 엄밀해인 현수곡선이론을 여러경우에 대하여 유도하고 그 오차를 계산하였다. 계산된 오차는 오차해석을 통하여 추측 될 수 있었으며 본 연구에서는 정의된 무차원군들과의 연관 성도 검토되었다.

• 한국의류학회지
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• 제46권3호
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• pp.454-463
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• 2022

This study aims to provide basic size data for the development of a hip dislocation prevention garment for cerebral palsy (CP) children and useful information for the design of garment products for CP children through identifying differences in body shape between CP and non-CP children and reviewing the tibial-stature prediction formulas of previous studies. Forty-seven Korean children with CP aged 2 to 14 years were measured for body size from October 2019 to August 2020. Body measurements of 18 sites, including greater trochanter length, which is an important site for a hip dislocation prevention garment, were collected and analyzed. Data of non-CP children were taken from same age of Size Korea and compared. Tibial-stature prediction formulas suggested in four previous studies were also reviewed. CP children had significantly lower stature as well as circumferential dimensions when compared to non-CP children. Greater trochanter length is difficult to predict through other body dimensions. Thus, direct measurement is required. Of the general key dimensions used in the clothing industry, only hip circumference could explain the body shape of CP children. Tibial-stature prediction formulas cannot always but tend to largely predict the actual stature of CP children.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.835-837
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• 2002

This paper presents a shape optimization algorithm of electromagnetic devices using the design sensitivity analysis with FEM. The design sensitivity and adjoint variable formulas are derived for the 3D FEM with edge element. This algorithm is applied to 3D electro-magnet pole shape optimization problem to make a uniform flux density at the target region.

• 제어로봇시스템학회논문지
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• 제11권1호
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• pp.9-12
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• 2005

This paper presents an LMI-based method to design sliding mode observers for a class of uncertain systems. Using LIs we derive an existence condition of a sliding mode observer guaranteeing a stable sliding motion. And we give explicit formulas of the observer gain matrices. We also consider sliding mode observer design problems under an α-stability constraint or an LQ performance bound constraint. Finally, we give a numerical design example.

• Steel and Composite Structures
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• 제5권1호
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• pp.71-86
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• 2005

Based on the test data of Nippon Steel Corporation, the formulas for calculating mechanical properties of fire-resistant (FR) steel at elevated temperatures have been established. A practical approach for fire safety design of FR steel members, including axially compressed members, flexural members and eccentrically compressed members, is developed in this paper. Compared with the full-scale specimen experiments and FEM numerical analysis, this practical approach for fire safety design of FR steel members is demonstrated to be effective and precise.

• 한국항해학회지
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• 제22권2호
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• pp.33-38
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• 1998

Approximate design formulse for bandpass filter using stepped microstrip lines are derived. The coupling length of which can be adjusted according to the factor K.Some advantages fo this filter, thus, are the abilities to control the size and shape by changing the structure of the resonator. Using the design formulas an experimental filter was designed and fabricated . The experimental results have been agree with the designed ones, and hence, the validity of the proposed method has been confirmed.

• 제어로봇시스템학회논문지
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• 제12권11호
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• pp.1057-1060
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• 2006

This paper presents an LMI-based method to design a reduced order observer based sliding mode controller for a class of uncertain systems. Using LMIs we derive an existence condition of a reduced order observer and a sliding mode control law. And we give explicit formulas of the gain matrices. Finally, we give a numerical design example, together with a design algorithm.