• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.4
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• pp.128-136
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• 2006

The purpose of this paper is to examine the dynamic stall characteristics of an elliptic airfoil when subject to constant pitch motions. In this study, which was motivated by the pressing need for a greater understanding of the reduced frequency$({\kappa})$ effects on flow patterns of elliptic airfoil, the various reduced frequencies were considered. The result confirms that the reduced frequency has a profound effects on the flow patterns. The increase of ${\kappa}$ accelerate the separation bubble bursting process up to ${\kappa}=0.10$, then diminish with further increase in ${\kappa}$. Compared with static condition, the dynamic pitching airfoil delays stall angle approximate $4{\circ}{\sim}5{\circ}$ during pitch-up stroke for ${\kappa}=0.10$. Results from this qualitative analysis provided valuable insight Into the control of dynamics stall.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.805-807
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• 2011

In this paper, we propose a method to inspect defects of injection molded automotive parts. In order to inspect them, we developed and used a line detection algorithm and a defect analysis algorithm. The line detection algorithm defines center point of a laser line and the inspection algorithm determines the defects of automotive parts using pattern data of inspected objects and the data results from the line detection algorithm. We evaluated the accuracy and the processing time of inspection and they showed good performance.

• Fashion & Textile Research Journal
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• v.18 no.1
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• pp.27-37
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• 2016

This study examined consumer perceptions towards outdoor wear differentiation and product attributes for outdoor wear differentiation to develop an outdoor wear differentiation strategy. It also investigated how consumer's evaluated product attributes according to consumer's demographic characteristics. Data were acquired from a survey of 454 adult respondents aged over 20 that was analyzed with descriptives, frequency, t-test, one-way ANOVA, factor analysis, and reliability. The results were as follows. First, it showed that consumers did not have a positive or a negative perception toward outdoor wear differentiation, and they thought outdoor wear should be differentiated. Those married and older tended to think that outdoor wear should be differentiated more than that for those single and younger. Consumer evaluations were significantly different on the necessity of outdoor wear differentiation according to age and total income. Second, consumers assessed that color, pattern and textiles had similar characteristics among outdoor wear brands; in addition, brand recognition and brand image had very different characteristics. Third, product attributes for outdoor wear differentiation were service and store, product quality, brand and popularity, and product designs with mean values of product quality, product design, service and store, and brand and popularity, respectively. Fourth, consumers were significantly different in the importance assessment of product attributes for differentiation according to gender, marital status and age.

• Journal of the Optical Society of Korea
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• v.17 no.3
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• pp.255-261
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• 2013

Scene-based nonuniformity correction techniques for infrared focal-plane arrays have been widely considered as a key technology, and various algorithms have been proposed to compensate for fixed-pattern noise. However, the existed algorithms' capability is always restricted by the problems of convergence speed and ghosting artifacts. In this paper, an effective scene-based nonuniformity correction method is proposed to solve these problems. The algorithm is an improvement over the constant statistics method and a temporal median is utilized with the Gaussian kernel to estimate the nonuniformity parameters. Also theoretical analysis is conducted to demonstrate that effective ghosting artifacts elimination and superior convergence speed can be obtained with the proposed method. Finally, the performance of the proposed technique is tested with infrared image sequences with simulated nonuniformity and with infrared imagery with real nonuniformity. The results show the proposed method is able to estimate each detector's gain and to offset reliably and that it performs better in increasing convergence speed and reducing ghosting artifacts compared with the conventional techniques.

• Fashion & Textile Research Journal
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• v.10 no.2
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• pp.155-163
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• 2008

The college students selected by random sampling were classified into several groups by their cosmetic impulse buying pattern and the internal characteristics that cause them. Their shopping orientation, life styles, makeup self-confidence, makeup interest and self-image were the subjects of comparative analysis. The results of this research can be summarized as follows.; fashion leader was classified fashion dual leader, fashion opinion leader, fashion innovator and fashion follower. The fashion dual leader and fashion innovator were more impulse buying orientated. The fashion dual leader and fashion innovator were highly evaluated in intellectual self faithfulness and life decoration preference style. The fashion dual leader and fashion innovator attached great importance to leisure pursuit and name brand preferring shopping. They showed the tendencies to the makeup self-confidence and makeup interest. But the fashion follower showed quite different tendencies. The fashion dual leader and fashion innovator perceived themselves as varied life style. These internal characteristics were supposed to contribute to their impulse buying.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.403.1-403.1
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• 2014

In conventional far-field microscopy, two objects separated closer than approximately half of an emission wavelength cannot be resolved, because of the fundamental limitation known as Abbe's diffraction limit. During the last decade, several super-resolution methods have been developed to overcome the diffraction limit in optical imaging. Among them, super-resolution optical fluctuation imaging (SOFI) developed by Dertinger et al [1], employs the statistical analysis of temporal fluorescence fluctuations induced by blinking phenomena in fluorophores. SOFI is a simple and versatile method for super-resolution imaging. However, due to the uncontrollable blinking of fluorophores, there are some limitations to using SOFI for several applications, including the limitations of available blinking fluorophores for SOFI, a requirement of using a high-speed camera, and a low signal-to-noise ratio. To solve these limitations, we present a new approach combining SOFI with speckle pattern illumination to create illumination-induced optical fluctuation instead of blinking fluctuation of fluorophore.. This technique effectively overcome the limitations of the conventional SOFI since illumination-induced optical fluctuation is possible to control unlike blinking phenomena of fluorophore. And we present the sub-diffraction resolution image using SOFI with speckle illumination.

• The KIPS Transactions:PartB
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• v.13B no.3 s.106
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• pp.315-322
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• 2006

Ant Colony System(ACS) is easily applicable to the traveling salesman problem(TSP) and it has demonstrated good performance on TSP. Recently, ACS has been emerged as the useful tool for the pattern recognition, feature extraction, and edge detection. The edge detection is wifely utilized in the area of document analysis, character recognition, and face recognition. However, the conventional operator-based edge detection approaches require additional postprocessing steps for the application. In the present study, in order to overcome this shortcoming, we have proposed the new ACS-based edge detection algorithm. The experimental results indicate that this proposed algorithm has the excellent performance in terms of robustness and flexibility.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.9
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• pp.1015-1027
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• 2011

This study analyzes consumer-based apparel design elements and evaluation criteria using qualitative research methodology. Apparel design is one of the most important factors to determine consumer consumption and attitude; however, limited studies have examined them. This study provides essential cues for an apparel industry suffering from dramatically fluid market situations. Based on a qualitative analysis of the focus group interviews, researchers establish three categories (basic elements, elements generated by apparel, and elements experienced by consumer) of apparel design elements that are consistent with nine elements (shape, materials, color, pattern, detail, subsidiary materials, overall image & style, fit, and overall balance). The results provide 137 types of conceptualized apparel design evaluation criteria. They developed 56 initial themes, 23 evolved themes, 23 sub categories, and 12 kinds of theme categories with abstract conceptualization. This study explicates the critical role that consumer-based apparel design is the competitive advantage within the apparel industry.

• Korean Journal of Materials Research
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• v.17 no.8
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• pp.408-413
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• 2007

Process of the hydroxyapapite(HA) precipitation on bioactive titanium metal prepared by NaOH in a modified-simulated body fluid(mSBF) was investigated by high resolution transmission electron microscope (HRTEM) attached with energy dispersive X-ray spectrometer(EDX). The amorphous titanate phase on titanium surface is form by NaOH treatment and an amorphous titanate incorporated calcium and phosphate ions in the liquid to form an amorphous calcium phosphate. With increasing of soaking time in the liquid, the HA particles are observed in amorphous calcium phosphate phase with a Ca/P atomic ratio of I.30. The octacalcium phosphate (OCP) structure is not detected in HRTEM image and electron diffraction pattern. After a long soaking time, the HA particles grow as needle-like shape on titanium surface and a large particle-like aggregates of needle-like substance were observed to form on titanium surface within needle-like shape. A long axis of needle parallels to c-direction of the hexagonal HA structure.

• Macromolecular Research
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• v.12 no.4
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• pp.374-378
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• 2004

The biodegradable and biocompatible poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a copolymer of microbial polyester, was fabricated as nanofibrous mats by electrospinning. Image analysis of the electrospun nanofibers fabricated from a 2 wt% 2,2,2-trifluoroethanol solution revealed a unimodal distribution pattern of fiber diameters with an observed average diameter of ca. 185 nm. The fiber diameter of electrospun fabrics could be controlled by adjusting the electro spinning parameters, including the solvent composition, concentration, applied voltage, and tip-to-collector distance. Chondrocytes derived from rabbit ear were cultured on a PHBV cast film and an electrospun PHBV nano-fibrous mat. After incubation for 2 h, the percentages of attached chondrocytes on the surfaces of the flat PHBV film and the PHBV nanofibrous mat were 19.0 and 30.1 %, respectively. On the surface of the electrospun PHBV fabric, more chondrocytes were attached and appeared to have a much greater spreaded morphology than did that of the flat PHBV cast film in the early culture stage. The electro spun PHBV nanofabric provides an attractive structure for the attachment and growth of chondrocytes as cell culture surfaces for tissue engineering.