• 복식문화연구
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• 제31권5호
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• pp.627-639
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• 2023

This study seeks to increase the satisfaction of elderly men when purchasing and wearing ready-to-wear clothes by designing a slacks pattern suitable for their body type, which is determined by analyzing their lower bodies using virtual avatars and 3D virtual simulation system. The study found the following. First, based on virtual visualization of the comparison slacks pattern, the waistline position was consistently the lowest scored question among the evaluation survey items. Interpretation of this dissatisfaction suggests that, because the front waistline falls below the abdomen, the lower body, and especially the abdominal shape, is unpleasantly emphasized. Second, by using a virtual simulation system, the study developed a new slacks pattern that considered the concerns of elderly men. The primary measurement changes were as follows: front waist girth W/4+1.5cm+0.5cm, back waist girth W/4+1.5cm-0.5cm, front hip girth H/4+2.5cm-0.5cm, back hip girth H/4+2.5cm+0.5cm. Third, the new slacks pattern's appearance was evaluated more highly than the comparison pattern, confirming the new pattern's appropriateness for elderly men. This study demonstrates how slacks and other clothing patterns designed in a 3D virtual garment simulator can be used to design more appealing clothing for elderly men, increasing the satisfaction of wearing ready-made clothes at older ages.

• 제어로봇시스템학회논문지
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• 제10권1호
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• pp.54-59
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• 2004

We suggest a 3D vision inspection algorithm which is based on the external shape feature. Because many electronic parts have the regular shape, if we have the database of pattern and can recognize the object using the database of the object s pattern, we can inspect many types of electronic parts. Our proposed algorithm uses the geometrical pattern matching method and 3D database on the electronic parts. We applied our suggested algorithm fer inspecting several objects including typical IC and capacitor. Through the experiments, we could find that our suggested algorithm is more effective and more robust to the inspection environment(rotation angle, light source, etc.) than conventional 2D inspection methods. We also compared our suggested algorithm with the feature space trajectory method.

• 한국정밀공학회지
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• 제21권7호
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• pp.83-91
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• 2004

The determination of camera position and orientation from known correspondences of 3D reference points and their images is known as pose estimation in computer vision or space resection in photogrammetry. This paper discusses estimation of transform parameters using the pattern matching method with 2D images only. In general, the 3D reference points or lines are needed to find out the 3D transform parameters, but this method is applied without the 3D reference points or lines. It uses only two images to find out the transform parameters between two image. The algorithm is simulated using Visual C＋＋ on Windows 98.

• 한국CDE학회논문집
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• 제6권2호
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• pp.133-139
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• 2001

Since a great number of 2D engineering drawings are being used in industry and at the same time 3D CAD becomes popular in recent years, we need to reconstruct 3D CAD models from 2D legacy drawings. In this thesis, a combination of a feature recognition method and an expert system is suggested for the 3D solid model reconstruction. Modeling primitives of 3D CAD systems are recognized and constructed by using the pattern matching technique of the features modeling. Additional information for the 3D model reconstruction can be generated by extracting symbols or text entities which are related to form entities. For complex and indefinite cases which cannot be solved by the process of feature recognition, an expert system with a rule base has been used for decision-making. A 3D reconstruction system which recognizes 2D DXF drawing files has been implemented where models composed with protrusions, holes, and cutouts can be handled.

• 한국전자파학회지:전자파기술
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• 제3권1호
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• pp.20-27
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• 1992

$\lambda$/2 다이폴 안테나 3개판 x,y,z축상에 서로 직교되도록 배열하여 각 소자의 수신 출력을 합성하므로써 등방성 패턴 안테나가 실현되었다. 각 소자는 H20MHz-895MHz익 서례 주파수 대역에서 임피먼스 정합플 양호하게 하고, 소자간의 상호 결합 효과를 최소로하기 위하여 슬리브 형태의 $\lambda$/2 다이폴 안테나를 사용하였다. 설계된 등방성 패턴 얀테나로 부터 복사된 충 전계의 세기는 원방계에서 각 촉상의 다이폴에 의해 발생 되는 Magnetic Vector Potential을 이용하여 계산하였다. 계산결과, 총 전계의 세기는 원점으포 부터의 거리에는 반비례하였고, 패턴상수 차이는 2.1dB이하이었다. 또한, x,y,z 축상에 배열된 안테나에서 수산된 합성전계의 편차는 2.8dB이하로 이론적 계산치와 O.7dB 정도의 차이가 있었다.

• 한국지식정보기술학회논문지
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• 제12권4호
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• pp.539-550
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• 2017

본 논문에서는 UHF대역 원통형 다이폴 배열 안테나에 대해서 설계, 제작 및 시험을 하였다. 제안하는 안테나는 원통형 다이폴을 수직으로 4단 배열하였다. 원통형 다이폴 내부에는 병렬구조 급전회로를 설치하여 광대역 매칭이 되도록 구현하였다. 급전회로를 원통형 다이폴 중심에 설치하여 방위각 방향 무지향 방사패턴의 이득평탄도 특성을 최적화하였다. 급전회로에서 분기되는 신호의 차이를 최소화하여 대칭적인 방사패턴을 구현하였다. 요구 규격은 UHF대역에서 대역폭 11.2% 이상, 이득 6dBi 이상, 2:1 이하의 정재파비, 수평방향 방사패턴 이득평탄도 ${\pm}1dB$ 이내, 고각 방향 방사패턴 3dB 빔폭 13도 이상이다. M&S를 통해서 구현 가능성을 확인하고, 제작 및 시험을 통해서 M&S 결과를 검증하였다. 시험결과는 UHF대역에서 대역폭 11.2%, 이득 6.30~8.31dBi, 정재파비 1.53:1 이하, 방위각 방향 방사패턴 이득평탄도 ${\pm}0.2dB$ 이내, 고각 방향 방사패턴 3dB 빔폭은 15.62~15.84도이다. 시험결과 모든 규격을 충족하였다.

• 한국통신학회논문지
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• 제41권12호
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• pp.1748-1751
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• 2016

본 논문에서는 휘어지거나 굴곡진 array인 3차원 conformal array의 beam pattern을 보정하고자 interpolation technique을 3차원으로 확장하여 3-D uniform rectangular array(3-D URA)에 적용하는 방법을 연구하였다. 시뮬레이션 결과는 2차원 interpolation 결과보다 매우 우수한 특성을 보여준다.

• 소성∙가공
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• 제31권2호
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• pp.89-95
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• 2022

3D printing products manufactured by material extrusion are used in many industrial fields recently. However, these products are difficult to use in the field due to their low tensile strengths. In order to solve this problem, research on improving the tensile strength of the output using a 3D printer has been continuously conducted. In this study, we performed a tensile test using Universal Testing Machine according to infill pattern, nozzle temperature, bed temperature, and printing speed conditions. Results revealed that tensile specimen of concentric shape had the highest tensile strength in infill pattern condition and that the tensile strength increased linearly with increasing nozzle and bed temperatures. However, the tensile strength decreased with increasing printing speed. Consequently, we confirmed that tensile strength could be increased and decreased depending on output conditions of 3D printing.

• 한국지역사회생활과학회지
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• 제28권4호
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• pp.505-514
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• 2017

Although studies on the development of cool touch fabrics have been conducted widely, the effects of fitted pattern on enhancing the cooling sensation are insufficient. To investigate the effect of cool-touch fabric and fit of women's sports underwear, 3D and 2D patterns of sleeveless top and sports leggings were constructed. The performance of cool touch was tested by the Qmax value and wear test with nine subjects. Objective fit evaluation was observed by 3D virtual clothing using Clo software. Subjects rated wearing sensation such as 'cooling sensation, fit, wear comfort and preferences of purchase' using Likert's scale in the environmental chamber at $25^{\circ}C$, 45 %RH. The Qmax value of the cool touch fabric was higher than that of the PET fabric, which was well reflected in 'cooling sensation', especially in the case of a tight-fitted 3D pattern. The cooling sensation of the cool-touch fabric was not significantly elevated with 3D tight pattern as long as the size of the 2D pattern was similar to that of 3D pattern. However, the purchase preference was highly correlated with 3D fit and wear comfort.

• 한국생활과학회지
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• 제21권2호
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• pp.299-314
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• 2012

The purpose of this study was to explore effects of pattern alteration using a virtual clothing simulation approach in combination with 3D analysis software. Three raglan sleeves of different patterns were worn by an avatar using virtual clothing simulation with silk and cotton as the test fabrics. It was observed that the silhouette and hemline shape were affected differently based on raglan sleeve pattern and fabric type. By examining clothing pressure distribution, the cotton fabric designs and pattern shapes provided for a variety of influences on armhole and bust regions as well as the back sleeve area. For representative locations, cross section circumstance, cross section area, and volume were measured by using 3D analysis and the resulting correlation between the 2D and 3D data were investigated. Among different fabrics, there was little difference between the 2D and 3D clothing surface area. However, when using 3D analysis, clothing volume was significantly affected by different fabrics and pattern types. By simultaneously adopting the virtual simulator and 3D analysis, quantitative assessment of virtual clothing simulation was successfully conducted. In light of the results of this study, the resulting methodology is expected to be used as a comprehensive evaluation tool for virtual clothing simulation wear testing.