• 전자공학회논문지SC
• /
• 제39권2호
• /
• pp.146-156
• /
• 2002

이 논문에서는 불규칙한 배선 구조에 대한 가상직선(virtual-straight line) 파라미터 추출 방법과 이를 이용한 새롭고 빠른 시간 영역에서의 시뮬레이션 방법론을 보이고 검증한다. 비선형인 트랜지스터의 특성을 고려한 인터컨넥트 회로의 시간영역에서의 신호응답은 모델차수감소법(model order reduction method)을 사용하여 수행된다. 모델차수감소법은 인터컨넥트 회로의 단위길이당 파라미터를 이용하므로 인터컨넥트의 길이가 서로 다르고 불규칙한 형태를 갖는 인터컨넥트에 대해서 직접적으로 모델차수감소법을 적용하기 위해 가상직선 모델을 사용하여 인터컨넥트의 파라미터를 추출한다. 또한 모델차수감소법은 일반적인 Berkeley SPICE의 모듈로 구성하여 인터컨넥트 회로의 시간영역 시간응답을 구하였으며 일반적인 회로 시뮬레이터인 HSPICE의 시뮬레이션 결과와 비교하여 잘 일치한다는 것을 보인다. 제안된 방법은 복잡한 다층 배선 구조에 대한 신속하고 정확한 시간영역 신호응답을 제공함으로써 고성능 VLSI 회로 설계에 유용하게 적용할 수 있다.

• International Journal of CAD/CAM
• /
• 제4권1호
• /
• pp.1-10
• /
• 2004

Through reviewing and comparing the current virtual shopping malls web sites integrated VR into E-commerce, this paper analyzed both the advantages and disadvantages of two kinds of methods for product presentation: 2D image based and 3D model based presentation method. Using the virtual shopping mall (EasyMall) as a showcase, we presented the architecture of the system and the development technologies, especially those in the mixed presentation method. The presentation and customization methods in the two related modules, including the PhoneShow for mobile phone and EasyShow for textile products, were discussed. It indicated that the integration of E-commerce with VR could provide consumers with virtual experience and intelligent service for business activities. Furthermore, the product presentation methods can be made available for use in different cases.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2005년도 추계종합학술대회
• /
• pp.1003-1006
• /
• 2005

Vertex shader of GPU in personal computer is advanced in functions as to be half of traditional fixed T&L functions. And, capacity of memory for saving resources to process instructions is unlimited. GPU that can be programmed by programmer is needed for mobile system as well as personal computer. In this paper, we implement software virtual machine for vertex shader using C++ Language. Our goal is designing hardware GPU that can apply to mobile system. The virtual machine consists of nVidia GPU instructions. Input Data to virtual machine is generated by Microsoft fxc compiler. That is to say, Input Data is compiled shader program written in HLSL, Cg, or ASM. The virtual machine will be a reference model for designing hardware GPU and can be used for Testbed to test added or modified instruction.

• 대한산업공학회지
• /
• 제31권1호
• /
• pp.36-43
• /
• 2005

It is the basic requirement of design process of parts assembly to specify geometric dimensions and tolerances of product characteristics. Among them, tolerance stack analysis is one of the important methods to specify tolerance zone. Tolerance stack analysis is to calculate gap using tolerances which includes geometric and coordinate dimensions. In this study, we suggested more general method called the virtual method to analyze tolerance stack. In virtual method, tolerance zone is formed by combination of dimensional tolerance, geometric tolerance and bonus tolerance. Also tolerance zone is classified by virtual boundary condition and resultant boundary condition. So gap can be defined by combination of virtual boundary and/or resultant boundary. Several examples are used to show the effectiveness of new method comparing to other methods.

• Journal of Power Electronics
• /
• 제13권3호
• /
• pp.479-486
• /
• 2013

This paper presents a control strategy for distributed systems, which can be used in islanded microgrids. The control strategy is based on the droop method, which uses locally measured feedback to achieve load current sharing. Instead of the traditional droop method, an improved one is implemented. A virtual inductor in the synchronous frame for three-phase inverters is proposed to deal with the coupling of the frequency and the amplitude related to the active and reactive power. Compared with the traditional virtual inductor, the proposed virtual inductor is not affected by high frequency noises because it avoids differential calculations. A model is given for the distributed generation system, which is beneficial for the design of the droop coefficients and the value of the virtual inductor. The effectiveness of the proposed control strategy is verified by simulation and experiment results.

• 한국의류학회지
• /
• 제32권2호
• /
• pp.340-347
• /
• 2008

A prototype of 3D clothing design system with a direct pattern development function was suggested, reflecting intuitive design functions and design modifications while considering the fit of clothing patterns with the 3D human body in the virtual 3D space. The research method was as follows. Clothing models were created using a 3D design tool, 3ds max on the surface of 3D human body model made by scanning an actual human body. 3D illustrations were completed by revising the fit and sizing of the human body and clothing models. 2D T-shirt pattern was produced 3D illustrations using from a 3D scanning data modeling solution RapidForm 2004, a 2D conversion program for 3D data called 2C-AN, and Yuka CAD. As a result, the following conclusions were made. The fit of the clothing and human body can be adjusted by reflecting individual body figure characteristics and 3D illustrations over the actual 3D body model. Furthermore, intuitive design support functions were intensified overcoming the weak point of existing 3D clothing design system by developing the direct clothing design in the virtual 3D space. 3D illustration design modifications can be directly reflected on clothing patterns from 3D illustrations by 3D clothing design system developed in this study.

• 한국산학기술학회논문지
• /
• 제12권11호
• /
• pp.5202-5207
• /
• 2011

여러 산업 분야에서 온도 제어 시스템 설계는 매우 중요한 문제이다. 시스템 개발을 위해서는 개념적인 디자인, 실제 테스트를 위한 시스템 구현, 반복적인 실험을 통한 제어기 설계용 수식모델 도출, 제어기 설계 및 성능 테스트의 과정을 거친다. 통상적으로 실제 테스트 시스템 구현 및 반복적인 실험을 통한 모델링, 제어기 설계 및 성능 테스트에 매우 많은 시간과 비용이 소요된다. 대부분의 온도 제어 시스템 설계 문제에서 동작 온도는 복사 열전달은 무시될 수 있는 범위이며, 히터는 듀티비를 이용하여 ON/OFF 방식으로 제어된다. 본 논문에서는 이러한 조건에서 개념적인 초기 시스템 디자인 후 제어기 설계용 모델 도출에서부터 제어기 설계 및 제어성능 예측까지의 전 과정을 자동으로 수행할 수 있는 기법을 제시하여 온도 제어 시스템의 초기 설계를 손쉽고 빠르게 검증 할 수 있도록 하였다. SISO (Single Input Single Output) 시스템을 예로 들어 제안한 기법의 유용함을 보였다.

• 한국의상디자인학회지
• /
• 제25권4호
• /
• pp.107-122
• /
• 2023

This study analyzed the style, dimensions, fabric patterns, colors, and fabrics of a traditional Chinese women's dress from the Zhou Dynasty, and reconstructed it in the form of a virtual garment using 3D CLO. Based on ancient flat image data and three-dimensional portrait data, who wore them, how they were worn, and how they were coordinated was analyzed. In order to analyze the size and pattern of the straight Ju Chines dress, data from the excavation report and the tomb owner's anthropometric measurements were combined to infer the wearing condition and organize the sculptural features. Dimensional analysis was carried out using a well-preserved small-scale woven cotton cloth as a restoration model, and the horizontal and vertical dimensions were reasonably estimated using the shape proportioning method. The analysis of the colors and patterns of the fabrics was based on the colors and patterns of the fabrics excavated from Masan Tomb No. 1 during the Eastern Zhou, Qin, and Han periods. Finally, a virtual model was created using data from the excavation report and the age and height information of the owner of the excavated robe, and the pose and size of the virtual model were determined using 3D CLO. Based on the previous research data, the garment was virtually sewn and simulated. The shape, pressure, and strain of the garment in different postures was also compared. Through the research direction of pattern and 3D restoration, this research maximizes the restoration of Chinese traditional women's dress and presents it in a more intuitive, comprehensive, and vivid way.

• 한국군사과학기술학회지
• /
• 제14권4호
• /
• pp.639-647
• /
• 2011

In this paper, we have designed the Anti-Aircraft Artillery(AAA) model for the surface-to-air virtual engagement. The AAA model for the virtual combat simulation needs to detect the present target and estimate the target flight trajectory to find the aiming point. To find collision point of projectile fired from the artillery with the moving air target, we have presented the estimating technique for artillery aiming point. And we have analyzed the target probability of kill using Calton Hit function. Anti-air threat envelops are presented when the target velocity, position and the arrangement of four AAA are varying. Then we have compared the analyzed result using developed model with AEM model of MSA program.

• 한국정보시스템학회지:정보시스템연구
• /
• 제31권4호
• /
• pp.145-160
• /
• 2022

Purpose The purpose of this study is to develop a virtual try-on deep learning model that can efficiently learn front and back clothes images. It is expected that the application of virtual try-on clothing service in the fashion and textile industry field will be vitalization. Design/methodology/approach The data used in this study used 232,355 clothes and product images. The image data input to the model is divided into 5 categories: original clothing image and wearer image, clothing segmentation, wearer's body Densepose heatmap, wearer's clothing-agnosting. We advanced the HR-VITON model in the way of Mixed-Precison, Gradient Accumulation, and sharing model weights. Findings As a result of this study, we demonstrated that the weight-shared MP-GA HR-VITON model can efficiently learn front and back fashion images. As a result, this proposed model quantitatively improves the quality of the generated image compared to the existing technique, and natural fitting is possible in both front and back images. SSIM was 0.8385 and 0.9204 in CP-VTON and the proposed model, LPIPS 0.2133 and 0.0642, FID 74.5421 and 11.8463, and KID 0.064 and 0.006. Using the deep learning model of this study, it is possible to naturally fit one color clothes, but when there are complex pictures and logos as shown in <Figure 6>, an unnatural pattern occurred in the generated image. If it is advanced based on the transformer, this problem may also be improved.