• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.5
• /
• pp.2357-2380
• /
• 2019

In this paper, we investigate the impact of hardware impairments (HWIs) on the performance of a downlink massive MIMO system. We consider a single-cell system with maximum ratio transmission (MRT) as precoding scheme, and with all the HWIs characteristics such as phase noise, distortion noise, and amplified thermal noise. Based on the system model, we derive closed-form expressions for a typical user data rate under two scenarios: when a common local oscillator (CLO) is used at the base station and when separated oscillators (SLOs) are used. We also derive closed-form expressions for the downlink transmit power required for some desired per-user data rate under each scenario. Compared to the conventional system with ideal transceiver hardware, our results show that impairments of hardware make a finite upper limit on the user's downlink channel capacity; and as the number of base station antennas grows large, it is only the hardware impairments at the users that mainly limit the capacity. Our results also show that SLOs configuration provides higher data rate than CLO at the price of higher power consumption. An approach to minimize the effect of the hardware impairments on the system performance is also proposed in the paper. In our approach, we show that by reducing the cell size, the effect of accumulated phase noise during channel estimation time is minimized and hence the user capacity is increased, and the downlink transmit power is decreased.

• Fashion & Textile Research Journal
• /
• v.23 no.2
• /
• pp.261-272
• /
• 2021

The purpose of the present study was to evaluate the thermal insulation of air-filled winter jackets according to the amount of air-filler using a thermal manikin. The insulation of these jackets' was compared to a down padded jacket with an identical design and size. The amounts of air-filler were 100% (26,219 cm³), 70% (18,645 cm³), 50% (13,110 cm³), and 0% (0 cm³). The results showed that a clothing insulation (Icl) of 0%, 50%, 70%, and 100% air, and 100% down jackets was 0.208, 0.243, 0.207, 0.176, and 0.315 clo, respectively. In addition, the down jacket with waisttaped had a clothing insulation of 0.369 clo. However, the highest value of clothing insulation per clothing weight was the 50% air-filled jacket in all conditions. In terms of regional power consumption of the thermal manikin, the down jacket consumed less power for the shoulder and chest than the air-filled jackets. In conclusion, in order to maximize the thermal insulation of air-filled jackets, an optimal amount of air-filler, that is, an amount which does not compromise (break) the layer of inner air between the surface of manikin and the lining of the jacket, should be explored. Further studies on lining materials, end-closed design, and changes in thermal insulation under the conditions of strong wind or heavy snow are recommended.

• The Research Journal of the Costume Culture
• /
• v.31 no.1
• /
• pp.124-140
• /
• 2023

This study analyzes traditional women's Hu costumes of the Tang dynasty, and deploys a creative fashion design to converge contemporary and traditional styles. In this costume, women wear a robe with striped or plain patterns in the lower part of the pants, and it appears frequently in red and yellow colors. Depending on the sleeve, it is either a round collar or a turn down collar robe. In the Hu hat, the huntuomao and juanyanxumao were leather and mili and weimao were used to prevent the sand from flowing. This study uses the CLO 3D program with the "moment" theme based on the Hu costume for women to deploy 4 pairs of fashion design and to produce works for 2 pairs. The 3D virtual clothing program demonstrates important effects in design deployment and pattern arrangement through its efficiency and convenience of clothing production. The CLO 3D program was closely combined with the 2D design and the 3D affect, and it heightened the efficiency in saving the processing time and energy of the sample clothes. Through facilitating the 3D digital fashion design, the production may reduce time needed and contribute to an effective economy, and it may compare digital fashion design to actual products as well as illustrate the potential of digital fashion design.

• The Research Journal of the Costume Culture
• /
• v.31 no.6
• /
• pp.720-737
• /
• 2023

This study aims to merge Picasso's expressive elements and deconstructive fashion's formative traits, proposing an upcycle fashion design that fuses artistic and philoso-phical aspects. The analysis of Picasso's Cubism identified qualities like liberating revolution, fluidity of vision, geometric reducibility, complex symbolism, and creative imitation. The analysis of Derrida's deconstructionism revealed expressive traits: uncertainty, intertextuality, différance, and dis-de phenomenon. An upscale fashion design was developed based on six Picasso works featuring women. The design was created using the fashion design software CLO 3D and integrated clothing waste and scrap fabrics as materials.The results are as follows. First, upcycle fashion was viewed from a new perspective based on Picasso and Derrida's values. This perspective suggested creating better ethical values by upholding environmental protection in novel ways that overcome limitations rather than destroy existing values indiscriminately. Second, upcycle fashion design methodologies were derived from various perspectives utilizing formative features of Picasso's works and specific expressive features of deconstructed fashion. Third, the direction of mitigating waste and pollution from clothing production and transportation was revealed by making clothes in a virtual space using the CLO 3D program. This study contributed to obtaining various methods for developing upcycle fashion designs using own methods of Picasso and Derrida to diversify the approaches of upcycling, which is relatively stagnant in disassembling.

• Fashion & Textile Research Journal
• /
• v.25 no.5
• /
• pp.593-602
• /
• 2023

This study aimed to facilitate the use of virtual technologies such as sewing, appearance, and material expression in 3D virtual wear programs. For product production and education, we expounded how to express the shoulder shape and silhouette of sleeve-expanded power shoulder jackets. Two designs of sleeve-expanded power shoulder jackets were selected, and virtual jackets were produced using a virtual avatar based on the body dimensions of female subjects in their 20s. The essential purpose of a 3D virtual power shoulder jacket is to express the shoulder angle rise and shoulder width, which are much wider than the avatar's shoulder. Therefore, the virtual pad values were adjusted for the collision and rendering of each thickness. In addition, the position and angle of the virtual pads were controlled through simulation. Appearance similarity was evaluated using photographic data and the virtual jackets. For the set-in sleeve virtual power shoulder jacket, the wrinkle expressions of the torso and sleeve were rated as moderate, and material expression was slightly insufficient. The similarity of some ease and width items of the torso was tightly expressed, and the overall appearance, positions of lines, and details of jackets were rated high, especially at the neck and sleeve shapes. In the case of the kimono virtual power shoulder jacket, the expressions of the torso wrinkles and buttons were slightly lower; however, the overall similarity, basic lines, ease, shoulder and neck details, and material expression of the virtual jackets were highly evaluated.

• Korean Journal of Agricultural Science
• /
• v.50 no.4
• /
• pp.663-673
• /
• 2023

The purpose of this study was to scientifically activate the forest healing program activities for the elderly. The predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD), which are indices of thermal comfort in the thermal environment, and degree of canopy closure were compared and analyzed. Based on this information, the study objective was to present the appropriate conditions for maintaining the best comfort for the elderly. Six deck road shelters, which are the most active locations in forest healing programs among the National Center for Forest Therapy, were selected as the study sites. The results indicated that in the case of the conditions of 1 clo (clothing insulation value) and 1 met (metabolic rate) at an air temperature of 19 to 21 degrees in September on the measurement date, the PMV values ranged between -1.85 and -0.98 at all sites, and PPD values ranged between 25.60% and 68.68%. On the other hand, in the case of 1.3 clo and 1.6 met conditions, the PMV values ranged between -0.08 and 0.23 for all sites and PPD values ranged between 5.40 and 6.18. As shown above, the difference in thermal environment comfort and satisfaction according to the condition of the amount of metabolism and the amount of clothing could be confirmed. In addition, an analysis of the relation between PPD and canopy closure suggested a significantly positive correlation between them, and it was found that canopy closure was a factor affecting thermal comfort. Studies on effects of forest thermal environmental comfort and canopy closure on forest healing program areas should be conducted extensively according to seasonal conditions to provide information that can be used for more effective forest healing programs.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.25 no.4
• /
• 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.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.25 no.4
• /
• pp.123-132
• /
• 2023

The term 'module' is an architectural term. It refers to the components or systems that make up a finished product. As industries develop, modules have become one of the methods that can create diverse and creative designs. Traditional modular fashion design mainly focused on structural methods, such as the combination, assembly, overlap, and arrangement of modules, as well as the tessellation of geometric shapes. However, in this paper, significance lies in exploring the application of shape grammar, a design method in architecture, to fashion design. It aims to search for ways to express three-dimensional designs, derive designs that can be worn and produced, and propose fashion design by applying the rules of shape grammar to the design process. Through this analysis, the paper aims to examine the methods and characteristics of shape grammar. The research method of this paper is as follows. First, by utilizing optimized programs for implementing the modules of shape grammar, it was possible to propose a method for producing modules of shape grammar and suggest module designs. Additionally, effective methods of representation using the Clo 3D program were explored in the design development process. Second, by applying shape grammar to the fashion design process, five-dimensional modular fashion designs were proposed, including a bolero, dress 1, dress 2, setup, and coat. The proposed modular fashion design using shape grammar in this paper provides a rational design process that differentiates itself from traditional modular fashion design. By formalizing the shapes between modules and creating rules, it overcomes the limitations of design that rely on the designer's intuition or sensibility and enables the development of more diverse modular fashion designs. This application of shape grammar in fashion design can provide an important direction in exploring a sustainable fashion industry.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.25 no.4
• /
• pp.13-28
• /
• 2023

The purpose of this study is to analyze the characteristics of hippie style in emerging brands pursuing the hippie spirit, examine the changes in hippie style, and apply them to the design development process to propose a hippie style design that reflects contemporary characteristics. The research method of this study was used to grasp the characteristics and current status of hippie style based on a literature review and prior research. Through the analysis of Bode and Story mfg, a new brand that reflects the hippie spirit, the design expression methods and characteristics of modern hippie style were derived, and based on the analysis, the design of the 3D CLO virtual outfit was developed. The results of the study are as follows. First, in addition to the use of eco-friendly materials, the digital technology of the CLO 3D program was applied to the design development process, which made it possible to increase sustainability from the production process. Second, by creating a retro design centered on a striped pattern expressing freedom, revolution, and equality, and a handcrafted design based on a tie-dye pattern, the design was able to express the hippie spirit of loving nature, and through this, a new direction of eco-friendly and modern fashion design was presented.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.26 no.1
• /
• pp.17-31
• /
• 2024

The purpose of this study is to propose a modern use of traditional culture by developing creative fashion designs that combine modern and traditional styles based on an analysis of traditional costumes of women in the Tang Dynasty of China. The characteristics of the Tang Dynasty women's costume are as follows. The Tang Dynasty women's costume consists of a short coat (衫, Shan), skirt (裙, Qun), half-arm shawl (半臂, Banbi), and short embroidered cape (帔, Pei). The colors are succinct and elegant, commonly red, yellow, green and navy blue in its entirety. It may be classified by pattern that blend plant patterns, animal patterns, geometric patterns, and two or more mixed patterns. On the basis of the characteristics for traditional women's costume during the Tang Dynasty, the CLO 3D program is employed to develop digital fashion design for four pairs of 3D digital clothing and the production of two pairs of work product. The results are as follows. First, the development of fashion design reflecting the design characteristics of traditional women's clothing in the Tang Dynasty of China could be expressed as fashion design reflecting unique values while connecting tradition and modernity. Second, the 3D virtual clothing program displays an extremely important effect in design deployment and pattern arrangement by having efficiency and convenience in clothing production. The CLO 3D program is closely combined with the 2D design and 3D effect and heightened efficiency while being appropriate to realize sustainability while saving processing time and energy for the sample products. Third, the production of an actual product by facilitating the 3D virtual clothing design may lead to time savings and an effective economy and may allow for the comparison of digital fashion design and actual products as well as confirming the effects of digital fashion design.