• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.467-470
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• 2005

There are about 10 motors for tile actuator of the automation system in an auto-mobile recently. The performance of the motor-case is much related to the noise and the vibration of an auto-mobile Multi-Forming process is so much the better than existing deep-drawing or Multi-step forming by press by less cost, installation and staff. But there isn't the specific and general process design, so we aren't good at competition. So in the first step, I want to study about the core design for the multi-forming process. We can access by the elasto-plastic theory and the finite element method, and we use a commercial package of the Deform-2D and, Deform-3D which is based on three-dimensional elasto-plastic finite element, evaluated propriety oi the package. The evaluation of the package propriety was simulated by simple bending example. It was found the elasto-plastic theory was mostly in agreement with the simulation. We proposed that three type of section for the core and analyzed by finite element method (Deform-2D). We can get the best result with the ellipse type core. Then we apply the result of the preceding analysis to the finite element method (Deform-3D). In 3D-finite element analysis, we can get the result of 8/100mm-roundness. This result can help the improvement of the multi-forming process.

• Journal of the Korean Society for Heat Treatment
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• v.21 no.4
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• pp.183-188
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• 2008

Hot press forming allows geometrically complicated parts to be formed from sheet and the rapid cooling hardens them to extremely high strength. The main purpose of this research is to characterize Al coated layer in Al coated boron steel during hot press forming. For the hot press hardening experiment, test specimens were heated up to $810{\sim}930^{\circ}C$ and held for 3, 6 and 9 minutes, respectively. And then, some specimens were press hardened and others were air-cooled without any pressing for the comparison purpose. Al coated layer shows four distinct micro-structural regions of interest; diffusion zone, Al-Fe zone(I) low-Al zone(LAZ) and Al-Fe zone(II). Band-like LAZ is clearly shown at temperature ranges of $810{\sim}870^{\circ}C$ and sparsely dispersed at temperature higher than 900oC. The micro-cracking behavior in the Al coated layer during forming were also analyzed by bending and deep drawing tests. The strain concentration in softer LAZ is found to be closely related with micro-cracking and exfoliation in coated layer during forming.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.23-32
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• 2021

Semantic image segmentation technology in the field of computer vision is a technology that classifies an image by dividing it into pixels. This technique is also rapidly improving performance using a machine learning method, and a high possibility of utilizing information in units of pixels is drawing attention. However, this technology has been raised from the early days until recently for 'lack of detailed segmentation' problem. Since this problem was caused by increasing the size of the label map, it was expected that the label map could be improved by using the edge map of the original image with detailed edge information. Therefore, in this paper, we propose a post-processing algorithm that maintains semantic image segmentation based on learning, but modifies the resulting label map based on the edge map of the original image. After applying the algorithm to the existing method, when comparing similar applications before and after, approximately 1.74% pixels and 1.35% IoU (Intersection of Union) were applied, and when analyzing the results, the precise targeting fine segmentation function was improved.

• Geomechanics and Engineering
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• v.37 no.3
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• pp.223-241
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• 2024

Evaluating the performance of Tunnel Boring Machines (TBMs) stands as a pivotal juncture in the domain of hard rock mechanized tunneling, essential for achieving both a dependable construction timeline and utilization rate. In this investigation, three advanced artificial neural networks namely, gated recurrent unit (GRU), back propagation neural network (BPNN), and simple recurrent neural network (SRNN) were crafted to prognosticate TBM-rate of penetration (ROP). Drawing from a dataset comprising 1125 data points amassed during the construction of the Alborze Service Tunnel, the study commenced. Initially, five geomechanical parameters were scrutinized for their impact on TBM-ROP efficiency. Subsequent statistical analyses narrowed down the effective parameters to three, including uniaxial compressive strength (UCS), peak slope index (PSI), and Brazilian tensile strength (BTS). Among the methodologies employed, GRU emerged as the most robust model, demonstrating exceptional predictive prowess for TBM-ROP with staggering accuracy metrics on the testing subset (R² = 0.87, NRMSE = 6.76E-04, MAD = 2.85E-05). The proposed models present viable solutions for analogous ground and TBM tunneling scenarios, particularly beneficial in routes predominantly composed of volcanic and sedimentary rock formations. Leveraging forecasted parameters holds the promise of enhancing both machine efficiency and construction safety within TBM tunneling endeavors.

• Fashion & Textile Research Journal
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• v.14 no.5
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• pp.766-777
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• 2012

The 13 genre paintings by Junkeun Kim in the book "Korean Games(by Stewart Culin 1858~1929)" were used to study the late $19^{th}$ century's basic costumes and Games style in Korea. The people who appear in the paintings are 26 adult males, 2 minor males, 2 adult females and 3 kisaengs. Typical men wore 'Jeogori' which had various colors and white linings with a reached hip line, and knotted with a 'go-rum' on the right side. They also wore, white colored 'Baji' with colorful sash that were knot below knee or ankle together with 'Hang-jun' or 'Daenim'. They wore 'Beoseon'. Some men wore 'Po' whose colors were blue, green, indigo, white. The general women wore 'Jeogori' in deep green and light pink, indigo, green, red, and they matched with colors for 'Kit' and, 'Go-rum', 'Kut-dong' and its 'Go-rum' was short and narrow. It was so fit and short with narrow sleeve. It had 'Dunggun-kit'(round head collar) with white 'Dong-jung' and so it fit at neck. They wore 'Chi-ma' whose color was red, light green, or light indigo. It contrasted with 'Jeogori'. The width of 'Chi-ma' was big enough. Then white inner slacks came out under the skirt. Traditional Korean games can be classified according to age and gender. Then the games can be further classified into three categories : men's games, women's games, and games for all. The games for adult are an archery practice, hunting, shovel work with a karae, making a bow, drawing Jongkung-chart, Korean chess, playing paduk, and the Korean card game. A swing is a game for women. Games for both men and women are dice play, and domino game. Games for both adult and minor males are sledge, and tightrope walking. Through genre paintings in the $19^{th}$ century, I reached a conclusion that basic costumes are similar to 'Hanbok' at the present time and the method of wearing them has not changed much. It appears that the originality of traditional costumes has been maintained.

• Journal of Internet Computing and Services
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• v.21 no.4
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• pp.9-16
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• 2020

In the Image processing and computer vision, the problem of reconstructing from one image to another or generating a new image has been steadily drawing attention as hardware advances. However, the problem of computer-generated images also continues to emerge when viewed with human eyes because it is not natural. Due to the recent active research in deep learning, image generating and improvement problem using it are also actively being studied, and among them, the network called Generative Adversarial Network(GAN) is doing well in the image generating. Various models of GAN have been presented since the proposed GAN, allowing for the generation of more natural images compared to the results of research in the image generating. Among them, pix2pix is a conditional GAN model, which is a general-purpose network that shows good performance in various datasets. pix2pix is based on U-Net, but there are many networks that show better performance among U-Net based networks. Therefore, in this study, images are generated by applying various networks to U-Net of pix2pix, and the results are compared and evaluated. The images generated through each network confirm that the pix2pix model with Attention, R2, and Attention-R2 networks shows better performance than the existing pix2pix model using U-Net, and check the limitations of the most powerful network. It is suggested as a future study.

• Journal of Science Education
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• v.39 no.2
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• pp.180-208
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• 2015

The purpose of this study was to investigate secondary students' perception of a good secondary science classes. Subjects were 18 secondary students who enrolled in alternative school located in Korea. The instruments of this study was a questionnaire which consisted of 18 items on 4 domains. Also data were collected from in-deep interviews and students' drawing. The results of the study were summarized as follows; First, students explained that good schools have the characteristics of the interesting and respectful atmosphere. Also there are good relationships between teachers and students. Second, they emphasized that good teachers are humanistic teachers. Third, good science classes are based on the constructivism in terms of the education methods. The results suggest that it may be necessary to remodel the merits of the alternative schools to solve the problem of public school. It is important to develop expertise of the science teachers in alternative school through teacher education programs based on the constructivism. Also it is necessary to provide appropriate learning space and various media for effective science teaching and learning in alternative school.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.4 no.1
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• pp.89-111
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• 2009

Since the financial crisis in 1997, the Korean economy has a steady increase of people who tend to establish their own business by 2008. Business foundations can be divided into independent businesses and franchise businesses. This study focuses on what type of business owners among franchise enterprisers can achieve success. This is intended to reduce trial and error by drawing upon success factors in the stages of establishment, operation, and achievement based on a total sample of 350 individual business sites. The result shows that the success factors in the stage of establishment include (1) Preparation such as foundation education (2) Marketing capability (3) Appropriateness of Business Item (4) Other founder's entry barrier, conglomerate's entry regulation and (5) Head Office Support including service education, market survey education, marketing support. On the other hand, the success factors in the stage of operation include the supervisor capability, Marketing capability, Head Office Support, Customer Management Capability and Employee Satisfaction. Additionally after choosing the major factors according to each stage, multiple regression analysis was processed and interpreted. Finally, we believe that the franchise or independent business foundations can make a profit as well as increase continuous sales and customer satisfaction only with thorough and careful preparation in all stages of foundation and operation. This study is expected to contribute to those who prepare new business in franchise domain to minimize failures with deep consideration of the success factors in the franchise.

• Korean Journal of Materials Research
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• v.22 no.11
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• pp.591-597
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• 2012

For heat exchanger applications, 2-ply clad materials were fabricated by rolling of aluminum (Al) and mild steel sheets. Effects of annealing temperature on interface properties, especially on inter-layer formation and softening of strain hardened mild-steel, for Al/mild steel clad materials, were investigated. To obtain optimum annealing conditions for the Al/mild steel clad materials, annealing temperature was varied from room temperature to $600^{\circ}C$. At the annealing temperature about $450^{\circ}C$, an inter-layer was formed in an island-shape at the interface of the Al/mild steel clad materials; this island expanded along the interface at higher temperature. By analyzing the X-ray diffraction (XRD) peaks and the energy dispersive X-ray spectroscopy (EDX) results, it was determined that the exact chemical stoichiometry for the inter-layer was that of $Fe_2Al_5$. In some samples, an X-layer was formed between the Al and the inter-layer of $Fe_2Al_5$ at high annealing temperature of around $550^{\circ}C$. The existence of an X-layer enhanced the growth of the inter-layer, which resulted in the delamination of the Al/mild-steel clad materials. Hardness tests were also performed to examine the influence of the annealing temperature on the cold deformability, which is a very important property for the deep drawing process of clad materials. The hardness value of mild steel gradually decreased with increasing annealing temperature. Especially, the value of hardness sharply decreased in the temperature range between $525^{\circ}C$ and $550^{\circ}C$. From these results, we can conclude that the optimum annealing temperature is around $550^{\circ}C$ under condition of there being no X-layer creation.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.130-138
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• 2015

Korean movies with a great variety of styles have recently succeeded in drawing people's attention Rule number one is "the more entertainment, the more audiences". On the top of box offices are always the movies that have a number of spectacular scenes, pounding sounds and big budget characters. Hong Sang Su movies, however, receive attention from the public without above noted descriptions. One of his effective methods of expression is "realism" He has illustrated the trivial episodes with his own wits and ways. Not only has his style become famous and popular but he has many followers. He enjoys using ordinary emotion and sentiment that are likely to happen to everyone. This paper uses two tools. One is the traditional analysis of realism. The other is how he can approach the public meaningfully by listing common elements he frequently uses in his movies. Nevertheless, we can't fully understand his realism by explaining how he shows our everyday life and how much his movie looks like it. Though admitting there are so many preceding papers on his works but this paper will try to look deep into his realism through the analysis of Mise-en-Sc$\grave{e}$ne.