• Textile Coloration and Finishing
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• v.29 no.3
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• pp.139-147
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• 2017

In this study, interesting area of development is retro-reflective thin film and then slitting to form retro-reflective material to be conbined with other fibers to form having retro-reflective characteristics, which slitting yarn can then be to provide fabrics. Glass beads are microscopic spherical size with diameters ranging from several microns to several millimeters. Applying the effects of optical property, glass beads are consumed for road safety used to make traffic signs, safety clothing and others. Glass beads retro-reflective films can be turned into slit yarns through slitting yarn process. The slit yarns can be combined into textiles using diverse methods such as weaving to provide a fabric having retro-reflective characteristics. Lightness and Luminance was increased with decreasing of interval of slit yarn in the fabric. Also, the hue is shifted greenish and bluish with interval of slit yarn.

• Journal of information and communication convergence engineering
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• v.17 no.3
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• pp.221-226
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• 2019

In this work, a transmitter/receiver front-end module (T/R FEM) with an automatic Tx/Rx switching scheme for a 2.4 GHz microwave power transfer is developed for a retro-reflective beamforming scheme. Recently, research on wireless power transfer techniques has moved to wireless charging systems for mobile devices. Retro-reflective beamforming is a good candidate for tracking the spatial position of a mobile device to be charged. In Tx mode, the T/R FEM generates a minimum of 1 W. It also comprises an amplitude and phase monitoring port for transmitting RF power. In Rx mode, it passes an Rx pilot signal from a mobile device to a digital baseband subsystem to recognize the position of the mobile device. The insertion loss of the Rx signal path is 4.5 dB. The Tx and Rx modes are automatically switched by detecting the Tx input power. This T/R FEM is a design example of T/R FEMs for wireless charging systems based on a retro-reflective beamforming scheme.

• Human Ecology Research
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• v.61 no.3
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• pp.493-503
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• 2023

Since ISO 20471 regulations(2013) were enacted, high-visibility clothing made of fluorescent fabric and retroreflective materials has been standardized to distinguish the wearers from the surrounding background in a dark place and to protect them. Accordingly, we made high-visibility safety clothing based on the international standards, and examined the positions of the retro-reflective materials on the attached sites to evaluate the suitability of the positions, by 3 types of safety clothing and the body regions when the wearers work or move. Two retro-reflective films of 5cm-horizontal lines were attached to the front/back of the upper-wear, and the lower-wear. Vertical lines were attached from the shoulder to the horizontal waistline. To analyze the motion in 3-dimension, we took pictured infrared-reflective markers on the retro-reflective film covered with yellow-tape on the front-side when 6 subjects wearing experimental garments performed 6 types of motions. According to the metronome tempo, the motions were performed for 30 seconds and repeated 6 motions ①~⑥ by 3 experimental clothing. Among the 6 motions, significant differences in the appearance rate of the markers by body region during the motions were found in 5 types except for motion ③. Significant differences by the post-hoc test were shown in motions ④ and ⑥ as well. Therefore, for high-visibility safety clothing, it is necessary to anticipate the worker's motion and consider the attaching position of the retro-reflective material. It is considered desirable to attach the retro-reflective materials to several places where the clothing is hard to wrinkle.

• Applied Chemistry for Engineering
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• v.28 no.1
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• pp.35-41
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• 2017

Materials exposed to outside will deteriorate due to various weathering factors such as sunlight, heat, temperature, humidity and so on. Therefore, predicting speed of degradation and life time is a very important issue. This research uses retro-reflective sheets with white and green which are most commonly used colors to conduct the outdoor exposure test and acceleration test of xenon arc in Arizona state in the United States, Chennai in India, Sanary in France and Seosan in Korea to measure the reflective performance of retro-reflection. The accelerated factor was obtained by using regression analysis through reflective values obtained from the acceleration test of xenon arc from Seosan area. Also, by using solar uv program, the accelerated factor of various climate regions were obtained and it was confirmed that the accelerated factor of Senary was 1.04, Arizona 1.82, Chennai 1.92 times higher than that of Seosan.

• The Research Journal of the Costume Culture
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• v.17 no.1
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• pp.105-119
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• 2009

The purpose of this study is to grasp the aesthetic characteristics of the retro romantic fashion. As a result of study, three artistic characteristics of the retro romantic fashion were presented. First, retro romantic fashion has an exaggerated formativeness. Retro romantic fashion has overcome the confinement of the present to imitate the splendor and decorative style of the past which results in exaggeration. Exaggerated costume tends to be spaciously bigger and emphasizes one particular part which offers implicated significance for the space between the body and the costume. A new visual fashion is created through this space. Second, retro romantic fashion encompasses gorgeous decorativeness. From an artistic point of view, decorations are part of impulsively formulated art. Artistic effects of such decorations are uniformly confirmed in various artistic states. Therefore, through gorgeous decorations, retro romantic fashion rejects artificiality and lack of sensitivity for new effects of aesthetics through expression of stronger artistic and spiritual desires. Third, retro romantic fashion expresses pluralistic retro. The current society has left the formalities of the modernism for a pluralistic society where openness, diversity, and uniqueness are respected. Such components of the pluralistic society are repetitively used in fashion. Time reflective retro romantic fashion is being recreated by borrowing images rather than replaying the historical contents, with the style, silhouette, and specific items that swayed in the past, being combined with modern materials, techniques, and designs. Literature review were conducted for this study. Literature review on retro romanticism encompassed resources on aesthetics, literature and art, including national and international fashion related literatures.

• Textile Coloration and Finishing
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• v.35 no.2
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• pp.98-106
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• 2023

The recent surge in night walkers and pedestrian traffic accidents has led to an increased interest in retro-reflection-based products, leading to several studies on retro-reflection. Nonetheless, achieving high durability and dispersibility of retro-reflective glass beads in viscous polyurethane coating resin remains challenging. To address this issue, this study conduct to functionalize the surface of glass beads for covalent conjugation to coating resin to enhance their dispersibility and durability in the coating resin. The study evaluated the dispersibility, chemical composition, and retro-reflection properties of the functionalized glass beads and coating resin. The results showed that the functionalized glass beads conjugated to the polyurethane coating resin and exhibited excellent dispersibility, high durability, and maintained retro-reflection efficiency.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.160-170
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• 2002

Retroreflective article is different from other reflecting objects as it returns the incidence ray to the near of its source. This characteristic makes the retroreflectors have many applications in reflective highway signs, reflective vests, and other safety-relaxed items. These articles may have various shapes. However, the quantitative evaluation of performance for the best shape of retroreflector needs much time and cost for manufacturing prototypes and for performance experiments. In this work, we have developed a program for simulating the trace of ray entered into a retroreflective element, in order to determine the optimal shape of retro-reflection. We have also proposed new performance criterion of retroreflective articles, which can confide the range of incidence angle, instead of the criterion with the merely retroreflective strength.

• Korean Journal of Human Ecology
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• v.5 no.2
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• pp.75-91
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• 2002

The purpose of this research is to investigate and analysis the style of Audrey Hepburn(1929-1993), the most important style icon in the 1950s and '60s from the point of the style of dress in her films - Roman Holiday (1953), Sabrina (1954), Funny Face (1957) and Breakfast at Tiffany's (1966) and fashion activities, furthermore, to know the influence on the contemporary fashion. After 1960s, her style has been recreated by so many designers. In the 1980s, times influenced by post-modernism, there was also the effort to reconstruct the style in the 1950s again. At that time, some Hepburn styles-a reflective of the flamboyant and exaggerating trend in her ages-were appeared by a few designers in the 1980s. Over the 1990s' retro culture, there were a lot of efforts to reemerge the styles in the 1950 and '60s, they led to full-scale reconstruction of Hepburn style - a feeling of the elegance and intelligence harmonizing with the minimal and formal style. By the retro culture adding with the mainstream fashion trend of simpleness and comfort in the year 2000, Hepburn's casual style has been reconstructed to meet the modem need in the 21s1 century. Through these considerations, we could notice that Hepburn style has been recreating from various fashion fields harmonizing with the popular trend of the age.

• Korean Journal of Optics and Photonics
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• v.25 no.6
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• pp.334-339
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• 2014

In this paper, the optical properties of a miniature telecentric camera are studied analytically and experimentally. By means of optical properties, the luminous intensity of retro-reflection of a miniature telecentric optical system is investigated. First, from a simulation the theoretical value of the coefficient of luminous intensity of retro-reflection of a miniature telecentric system is estimated. Second, a miniature telecentric camera device is designed, and the value of the coefficient of luminous intensity of retro-reflection of the actual device is measured through experiment. From simulation and experiment, we found that both the estimated and observed values of the coefficient of luminous intensity of retro-reflection range from 0.002 to $0.03m^2/sr$ (P384200CPH: $0.0042-0.018m^2/sr$, P285200CPH: $0.0045-0.0297m^2/sr$, P321450S: $0.0021-0.00963m^2/sr$) at 1.4 to 4.9 arcminute. The results prove the significance of the mechanisms used to design the miniature telecentric camera, and the experimental method. Accordingly, with these significant results, this study contributes to the development of theory and practice in optical engineering science.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.9
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• pp.2191-2204
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• 1993

A sensor system has been developed to measure the posture(position and orientation) of mobile robots working in industrial environments. The proposed sensor system consists of a CCD camera, retro-reflective landmarks, a strobe unit and an image processing board. The proposed hardware system can be built in economic price compared to commercial vision systems. The system has the capability of measuring the posture of mobile robots within 60 msec when a 386 personal computer is used as the host computer. The experimental results demonstrated a remarkable performance of the proposed sensor system in the posture measurement of mobile robots - the average error in position is less than 3 mm and the average error in orientation is less than 1.5.