• Journal of Mechanical Science and Technology
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• 제19권2호
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• pp.549-557
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• 2005

The requirements of multi-resolution models of feature-based solids, which represent an object at many levels of feature detail, are increasing for engineering purposes, such as analysis, network-based collaborative design, virtual prototyping and manufacturing. To provide multi-resolution models for various applications, it is essential to generate adequate solid models at varying levels of detail (LOD) after feature rearrangement, based on the LOD criteria. However, the non-commutative property of the union and subtraction Boolean operations is a severe obstacle to arbitrary feature rearrangement. To solve this problem we propose history-based Boolean operations that satisfy the commutative law between union and subtraction operations by considering the history of the Boolean operations. Because these operations guarantee the same resulting shape as the original and reasonable shapes at the intermediate LODs for an arbitrary rearrangement of its features, various LOD criteria can be applied for multi-resolution modeling in different applications.

• 한국정밀공학회지
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• 제32권5호
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• pp.447-454
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• 2015

Design and application of hardware-in-the-loop simulation (HILS) for design of CNC-controlled machine tool feed drives is discussed. The CNC machine tool is a complex mechatronics system where the complexity results from the software-based controller composed of a variety of functionalities and advanced control algorithms. Therefore, using a real CNC controller in the control simulation has merits considering the efforts and accuracy of the simulation modeling. In this paper challenges in HILS for a CNC controlled feed drive, such as minimization of time delay and transmission error that are caused by discretization of the feed drive model, is elaborated. Using an experimental HILS setup of a machine tool feed drive applications in controller gain selection and CNC diagnostics are presented.

• 한국공작기계학회논문집
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• 제16권5호
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• pp.211-217
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• 2007

A nano-imprinting stage has been widely used in various fields of nanotechnology. In this study, an analysis method of a nano-imprinting stage machine using FEM and flexible multi-body kinematics and dynamics has been presented. We have developed a virtual imprinting machine to evaluate the prototype design in the early design stage. The simulation using CAE for the imprinting machine is not only to analyze static and dynamic characteristics of the machine but also to determine design parameters of the components for the imprinting machine, such as dimensions and specifications of actuators and sensors. Structural components as the upper plate, the rotator, the shaft and the translator have been modeled with finite elements to analyze flexibility effects during the precision stage motion. In this paper flexible multi-body dynamic simulation is executed to support robust design of the precision stage mechanism. In addition, we made the 4-axis stage model to compare the dynamic behavior with that of 3-axis stage model.

• 대한조선학회논문집
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• 제50권5호
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• pp.314-323
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• 2013

Production simulation technology is beneficial to solve the complicated and fluctuated problems in a shipyard. It takes too much time and effort to build simulation models in the field, though. This research proposes a feasible method to reduce the difficulties related to simulation modeling for the factory or shop capacity analysis. In addition, a proposed neutral data format for production information is efficient to manage information acquisition for simulation modeling automation. A panel block shop model is contributed to comparison between the conventional technique and the automated one. The automation technique is highly recommended to run a rapid simulation in the shipyard problem.

• 복식문화연구
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• 제14권1호
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• pp.40-47
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• 2006

Three-dimensional body scanners were used for years in the clothing manufacturing fields. The 3D body surface provide essential data to draft patterns for mass customization, virtual fit model, and computerized patternmaking systems. This research proposed the methods of drafting patterns for men's jacket by using three dimensional body scan data. Eight male subjects were scanned, the surface data was flattened. The differentials of the flattened body surface and the jacket draft were measured, and analyzed the regressions. To verify the fit of the patterns, the jacket was constructed by the regression formulae and tested by experts. The fit of the jacket were significantly improved rather than a ready-made suit especially the shoulder areas. This means that the methods that we proposed were good to improve the fit of the garments and could be used effectively to implement mass customization strategies in the apparel retail industry.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.988-991
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• 2015

3D 프린터란 3차원으로 특정 물건을 찍어내는 프린터로, 입체적으로 만들어진 설계도만 있으면 종이에 인쇄하듯 3차원 공간 안에 실제 사물을 만들어 낼 수 있는 기기다. 최근 3D 프린팅 기술은 의학 분야에서 다양하게 활용되고 있으며, 생체 의학적 응용은 지금까지 가장 중요한 연구 주제 중 하나로 주목 받아왔다. 3D 프린팅 기술은 의료 뿐 아니라 자동차, 항공, 선반 등 제조업 전반에 혁신적인 변화를 일으키고 있다. 현재 3D 프린터의 의료산업 적용 분야는 가상 시뮬레이션, 맞춤형의료보형물 제작, 의료 인력 교육 실습 등이다. 따라서 본 연구에서는 의료서비스를 위한 3D 프린팅 기술과 적용사례를 비교 분석하였다.

• Structural Engineering and Mechanics
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• 제39권1호
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• pp.77-91
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• 2011

A simply structural damage detection software is developed to identification damage in beams. According to linear fracture mechanics theory, the localized additional flexibility in damage vicinity can be represented by a lumped parameter element. The damaged beam is modeled by wavelet-based elements to gain the first three frequencies precisely. The first three frequencies influencing functions of damage location and depth are approximated by means of surface-fitting techniques to gain damage detection database of forward problem. Then the first three measured natural frequencies are employed as inputs to solve inverse problem and the intersection of the three frequencies contour lines predict the damage location and depth. The DLL (Dynamic Linkable Library) file of damage detection method is coded by C++ and the corresponding interface of software is coded by virtual instrument software LabVIEW. Finally, the software is tested on beams and shafts in engineering. It is shown that the presented software can be used in actual engineering structures.

• 한국컴퓨터정보학회논문지
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• 제27권1호
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• pp.61-67
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• 2022

본 논문에서는 시뮬레이션 프로그램 리소스의 일부를 모바일 환경으로 전환시킬 수 있는 모델을 제안한다. 최근 제조업에서 PLC를 컨트롤러로 사용하는 스마트 팩토리가 급속하게 확산되고 있다. 그러나 PLC 운영 인력의 부족으로 운영에 대한 어려움을 겪고 있는 상황으로, PLC 운영 교육에 대한 플랫폼이 필요한 실정이다. 현재 PLC와 관련된 대부분의 교육 플랫폼들은 2D를 기반으로 하고 있어 정확한 학습이 어렵고, 일반적인 PC 환경에서 시뮬레이션 프로그램들을 원격 교육에 적용하면, 모니터 상에 많은 요소가 표현되어 화면 전환이 불편하다. 제안 모델의 실험 결과 일반적인 상황에서 프레임 저하가 없다는 것의 확인하였고, 요청 프레임에 따른 응답 시간은 평균 102ms 으로 학습자가 시스템 지연을 체감할 수준은 아닌 것으로 판단하였다.

• 한국의류산업학회지
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• 제23권6호
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• pp.790-798
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• 2021

With digital technology innovation, increased data access and mobile network use by consumers, products and services are changing toward pursuing differentiated values for personalization, and personalized markets are rapidly emerging in the fashion industry. This study aims to identify trends in digital customized automation technology by deriving types of digital customizing and analyzing cases by type, and to present directions for the development of digital customizing processes and the use of technology in the future. As a research method, a literature study for a theoretical background, a case study for classification and analysis of types was conducted. The results of the study are as follows. The types of digital customizing can be classified into three types: 'cooperative customization', 'selective composition and combination', 'transparent suggestion', and automation technologies shown in each type include 3D printing, 3D virtual clothing, robot mannequin, human automatic measurement program, AR-based fitting service, big data, and AI-based curation function. With the development of digital automation technology, the fashion industry environment is also changing from existing manufacturing-oriented to consumer-oriented, and the production process is rapidly changing with IT and artificial intelligence-based automation technology. The results of this study hope that digital customized automation technology will meet various needs of personalization and customization and present the future direction of digital fashion technology, where fashion brands will expand based on the spread of digital technology.

• Advances in nano research
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• 제15권2호
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• pp.113-128
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• 2023

The advancement of theoretical research has numerous challenges, particularly with regard to the modeling of structures, in contrast to experimental investigation of the mechanical behavior of complex systems. The main objective of this investigation is to provide an analytical analysis of the static problem of a new generation of composite structure, namely, functionally graded FG graphene reinforced composite GRC coated plates/shells. A complex power law function is used to define the material's graduation. Investigations are conducted on Hardcore and Softcore coated FG plates/shells. The virtual work approach is used to perform the equilibrium equations, which are then solved using the Galerkin technique to account for various boundary conditions. With reliable published articles, the presented solution is validated. The effects of hardcore and softcore distributions, gradation indexes, and boundary conditions on the buckling, bending deflection and stresses of FG GRC-coated shells are presented in detail. Obtained results and the developed procedure are supportive for design and manufacturing of FG-GRC coated plates/shells in several fields and industries e.g., aerospace, automotive, marine, and biomedical implants.