• Proceedings of the KSME Conference
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.269-274
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• 2001

In order to reduce trial-and-errors in the die design and production, CAE systems for analysis of stamping tools have been introduced at the initial design stage recently. For optimal design, the CAE engineers may need to correct the meshes generated by automatic mesh generation programs. However, they may need help of CAD engineers as they are usually not skilled in manipulation of CAD systems. In order to get around these problems, automatic shell mesh modification method is proposed, which utilizes existing CAD/CAE package (in this study, I-DEAS) without user interaction. The developed method and optimization techniques are applied to a stamping die rounding optimization problem. The optimization results show that the manpower and the time required at virtual tryout can be reduced by using the developed systems.

• Journal of Drive and Control
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• 제15권3호
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• pp.1-7
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• 2018

Humanoid robots have fascinated many researchers since they appeared decades ago. For the requirement of both accurate tracking control and the safety of physical human-robot interaction, torque control is basically desirable for humanoid robots. Humanoid robots are highly nonlinear, coupled, complex systems, accordingly the calculation of robot model is difficult and even impossible if precise model of the humanoid robots are unknown. Therefore, it is difficult to control using traditional model-based techniques. To realize model-free torque control, time-delay control (TDC) for humanoid robot was proposed with time-delay estimation technique. Using optimal walking trajectory obtained by particle swarm optimization, TDC with proposed scheme is implemented on whole body of a humanoid, not on biped legs even though it is performed by a virtual humanoid robot. The simulation results show the validity of the proposed TDC for humanoid robots.

• Journal of the Korean Geotechnical Society
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• 제38권9호
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• pp.5-17
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• 2022

Recently, several studies have been conducted on virtual fixed-point and elastic soil spring methods to simulate the soil-pile interaction in response to spectrum analysis of pile-supported structures. However, the soil spring stiffness has not been properly considered due to the seismic load magnitude, and studies on the response spectrum analysis of pile-supported structures considering this circumstance are inadequate. Therefore, in this study, the response spectrum analysis was performed considering the soil spring stiffness according to the seismic load magnitude, and the dynamic behavior of the pile-supported structure was evaluated by comparing it with existing virtual fixed-point and elastic soil spring methods. Comparing the experiment and analysis, the moment differences occurred up to 117% and 21% in the virtual fixed-point and elastic soil spring models, respectively. Moreover, when the analysis was performed using an API p-y curve considering the soil spring stiffness according to the seismic load magnitude, the moment difference between the experiment and analysis was derived at a maximum of < 4%, and it is the most accurate method to simulate the experimental model response.

• The Journal of the Convergence on Culture Technology
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• 제8권5호
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• pp.279-284
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• 2022

As a study of the blended learning method on design education through the blended learning method, I would like to propose that more advanced learner-led customized design education is possible. Understanding in face-to-face classes and advantages in non-face-to-face classes can be supplemented in an appropriate way in remote classes. Advanced artificial intelligence and big data technology can provide personalized and subdivided learning materials and effective learning methods tailored to learners' levels and interests based on quantified data in design classes. In this paper, it was proposed to maximize the efficiency of the class by applying a method that exceeds the limitations of time and space through the proposal of the A La Carte model (A La Carte). It is a remote class that can be heard anytime, anywhere, and it is also possible to bridge the educational quality and educational gap provided to students living in underprivileged areas. As the goal of fostering creative convergence-type future talents, it is changing with a rapid technological development speed. It is necessary to adapt to the change in learning methods in line with this. An analysis of the infographic virtual space design and construction process through the A La Carte model (A La Carte) proposal was presented. Rather than simply acquiring knowledge, it is expected that knowledge can be sorted, distinguished, learned, and easily reborn with its own knowledge.

• Journal of the Ergonomics Society of Korea
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• 제26권1호
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• pp.103-109
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• 2007

Representative human models (RHMs), a group of digital human models which represent the people of the target population within a designated percentage (e.g., 95%), are used for ergonomic design and evaluation in virtual environments. The present study evaluated the grid approach, a RHM generation method, in terms of accommodation percentage. RHMs generated from the grid approach dramatically decreased the accommodation percentage of the target population as the number of anthropometric dimensions under consideration increased. For example, the accommodation percentages by RHMs generated by the grid approach were 95% for 3 key dimensions (selected among 10 anthropometric dimensions), 45% for 5 dimensions, and 10% for 10 dimensions. A standardized multiple regression analysis found that this decreasing accommodation percentage was caused by low correlations between key dimensions and other dimensions. The accommodation evaluation process used in the present study is applicable to evaluation of other RHM generation methods.

• Journal of the Korean Society of Propulsion Engineers
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• 제6권2호
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• pp.65-74
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• 2002

Optimal supersonic diffuser shape of integrated rocket ramjet engine was derived which maximizes the total pressure recovery. Mass flux is considered as a design constraint and the second oblique shock angle of the external ramp, the cowl-lip angle and the throat area are selected as design variables. Refined response surface method through design space transformation technique was developed and employed, and high confidence level of the regression model could be obtained. Genetic algorithm was implemented for both system optimizer and subspace regression model optimization. Virtual nozzle was located at the end of throat to adjust the back pressure. With only 20 aerodynamic analyses, optimal supersonic diffuser shape which has 14% improved total pressure recovery characteristics was successfully designed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제23권2호
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• pp.109-116
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• 2005

3D Spatial Data, namely 3D Urban CG model express the building, road, river in virtual world and accumulate, manage the data in the GIS system. It is important infrastructure which expected in many usages. Recently 3D CG urban model needs much manual effort, time and costs to build them. In this paper, we introduce the integration of GIS, CG and automatic production of the $\lceil$3D Spatial Data Infrastructure$\rfloor$. This system make filtering, divide the polygon, generate the outlines of the GIS building map, design the graphic and property information and finally make automatic 3D CG models.

• Journal of the Korean Society of Costume
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• 제65권5호
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• pp.62-73
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• 2015

The aim of this research is to propose the final shirt design modified for new senior women that fulfills their emotional and physical needs. The modifications were based on the results of in-depth interviews and literature search, and the study was conducted in order to understand the desires and preferences of senior women, as consumption of outdoor-wear by the group continues to increase. To develop the design of outdoor-wear that satisfies the physical and emotional qualities and preference of the new senior women, six different designs with lines, combined materials, as well as materials that were layered, pleated and draped were proposed using virtual-dressing simulation software. Then, the modified designs were derived from the six original designs by reflecting the opinions collected in the in-depth interviews with eleven women in their 50s. The responses in the interviewed showed a preference for lines, pleats and layers, as these features made the clothes look trendy, gave it a slender-look, and improved the body shape of the women. As the color is the critical factor for outdoor-wear, there was an overwhelming preference for primary colors by the women, which was in contrast to their color preference in general clothes. A sleeve design modification was proposed to convert the half-sleeves to 3/4-long sleeves in order to account for changes in body temperature at menopause, and to satisfy the aesthetic needs for covering wrinkles. Research of new senior outdoor-wear designs will help segment and differentiate strategies for the increasingly fierce competing outdoor market, as well as l provide directions in the design creation process using the simulation of 3D virtual model.

• The Research Journal of the Costume Culture
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• 제11권6호
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• pp.835-851
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• 2003

This study analyses patent information of apparel design using computer technology and researches the trend of patent application focused on International Patent Classification. In terms of trend by filling data, Patent application started first in 1974 and increased sharply in 1993 with 14 cases and increased to 25 cases in 2000. In case of Korea, they began somewhat late in 1996, but reached a similar level with the leading country in 2000. In terms of trend by applicant, Gerber Garment Technology, Inc. filed 7 cases TORAY IND INC, filed 6 cases Levi Strauss & Co. filed 4 cases, NEC HOME ELECTRONICS LTD filed 3 cases, TOYOBO CO LTD filed 3 cases. Japanese companies occupied 52% and United States's companies occupied 48%. In terms of trend by country, foreigner occupied 47% of the patents filed by United State. Japanese take up 10% of total patent of United States. Korean occupied 84% of total patent of Korea and foreigner, american occupied 16% of the patents filed by Korea. In regared to International Patent Classification, in the section level G filed 92 cases(53%). In class level, G06 marked the first place in United States, Japan, and Korea. In subclass level, G06F marksed the first place with 74 cases. G06T and A61B were regarded as the new technologies. The new technologies are representing the dimensions of garment or computer-rendered model, providing the virtual reality through the texture mapping, digital dressing room or virtual dressing, and performing or retriving display on a screen for the result of changing pattern ao dress design, The technologies of core patent are designing or producing custom manufactured item, providing or prealtering the data for pattern making and visually displaying, interactively generating or previewing of various articles.

• Journal of the Korean Society of Clothing and Textiles
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• 제31권3호
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• pp.463-474
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• 2007

With rapid expansion in e-retailing of apparel business, personalized fitting model service shows the possibility as the differentiated marketing strategy in cyber shopping. According as necessity of personalized fitting model construction rises, it is tried personalized fitting model creation in several fields such as computer engineering, mechanical engineering, information engineering. But, because existent study was concentrated only on human body modeling, it does not reflect average morphological characteristics of human body properly. In this study, we wish to examine if morphing is fit for expressing characteristic of average human body shape and suggest desirable morphing. We used 3-D scan data of 254 Korean middle aged men collected by Size Korea 2004. The result of this study are as follows: Lower body types were categorized by height hip girth and lower drop(hip girth-navel girth) which were main factors of lower body shape. Then each factor was divided into 3 groups respectively, 30% in the middle, over 30%, under 30%. In 27 groups, the group which belonged to 30% in the middle of height, 30% in the middle of hip girth, 30% in the middle of lower drop was selected as a representative group. We tested geometrical figure by differ volume, tilt, position of point. And we created a representative type of men's lower bodies by morphing the representative group and analyzed it's horizontal, vertical sections. A representative type which was created by morphing reflected a real body and changed realistically at the part of hip, crotch, calf muscle and so on. A cross sections of a representative type were similar to average cross sections of the representative group in size and shape. So it was proved that morphing was successful.