• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1106-1107
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• 2007

Planar magnetic based design technologies have been widely applied to power design for better cooling and ease of fabrication. The planar transformer and the planar inductor have a low profile characteristics compare to the conventional transformer which would be more cubical in volume. High frequency operation of magnetic components is a main key to achieve high power density of the power module. However, at a high frequency, the skin effect and the proximity effect have to be considered very significantly in magnetic design and also the parasitics in the converter cannot be ignored. This paper deals with the design and the experiment of planar integrated magnetic component. The optimal design for planar magnetics is summarized.

• International journal of advanced smart convergence
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• v.7 no.4
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• pp.161-168
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• 2018

Recently, the bio-sensing information systems for collecting and analysing human body information of a patient in real time in the field of medical information and healthcare information service are continuously increasing. Specially, various wearable devices such as a wrist, a garment, and a skin attachment type for supporting health information of a mobile user are rapidly increasing. Until now, there is no patch-type biometric information service model. Therefore, this paper presents a biometric information system model and the application examples to support biometric information sensing and health information service of mobile user with digital patch system as a new biometric information system. As a result, through this research, research issues based on digital patch system are searched to suggest the direction of continuous research.

• Journal of Korea Multimedia Society
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• v.14 no.4
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• pp.481-493
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• 2011

As the development of mobile devices, mobile phones are equipped with many features. Video-call feature is one of them. In this paper, we present distance measurement between speaker and smart-phone using multiple color spaces and multiple thresholds. first, detect face based on skin color information. and second, measure distance between speaker and smart-phone using the detected face region. Especially, the first considering point in the development of face area detection is real-time processing and the second point is robustness to solve the problems of face detection errors due to rapid change of object movement, lighting and background between adjacent frames.

• Smart Structures and Systems
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• v.8 no.1
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• pp.139-155
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• 2011

Polymeric thin-film assemblies whose bulk electrical conductivity and mechanical performance have been enhanced by single-walled carbon nanotubes are proposed for measuring strain and corrosion activity in metallic structural systems. Similar to the dermatological system found in animals, the proposed self-sensing thin-film assembly supports spatial strain and pH sensing via localized changes in electrical conductivity. Specifically, electrical impedance tomography (EIT) is used to create detailed mappings of film conductivity over its complete surface area using electrical measurements taken at the film boundary. While EIT is a powerful means of mapping the sensing skin's spatial response, it requires a data acquisition system capable of taking electrical impedance measurements on a large number of electrodes. A low-cost wireless impedance analyzer is proposed to fully automate EIT data acquisition. The key attribute of the device is a flexible sinusoidal waveform generator capable of generating regulated current signals with frequencies from near-DC to 20 MHz. Furthermore, a multiplexed sensing interface offers 32 addressable channels from which voltage measurements can be made. A wireless interface is included to eliminate the cumbersome wiring often required for data acquisition in a structure. The functionality of the wireless impedance analyzer is illustrated on an experimental setup with the system used for automated acquisition of electrical impedance measurements taken on the boundary of a bio-inspired sensing skin recently proposed for structural health monitoring.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.2A
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• pp.105-112
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• 2012

Face detection at a distance faces is very challenging since images are often degraded by blurring and noise as well as low resolution. This paper proposes an improved face detection method with AdaBoost filtering and sequential testing stages with color and shape information. The conventional AdaBoost filter detects face regions but often generates false alarms. The face detection method is improved by adopting sequential testing stages in order to remove false alarms. The testing stages comprise skin-color test and variable edge-mask filtering. The skin-color filtering is composed of two steps, which involve rectangular window regions and individual pixels to generate binary face clusters. The size of the variable edge-mask is determined by the ellipse which is estimated from the face cluster. The validation of the horizontal and vertical ratio of the mask is also investigated. In the experiments, the efficacy of the proposed algorithm is proved by images captured by a CCTV and a smart-phone

• Fashion & Textile Research Journal
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• v.19 no.1
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• pp.90-100
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• 2017

In this research, consumer awareness investigation and wearing test were carried out for obtaining useful data on the development of thermo-sensitive functional clothing material. A survey involved 216 people in Seoul and Kyeonggi-do, and 200 questionnaires data were analyzed by descriptive statistics and frequency using SPSS 17.0. Four healthy men in twenties were participated for wearing test. Subjects in normal loungewear were exposed to temperature change from the initial temperature $30^{\circ}C$ down to $5^{\circ}C$ for an hour in a climate chamber. The environmental temperature, surface temperature of garment and skin were measured. As a result, most of respondents have all season clothing products such as underwear, hosiery, and jogging suit for loungewear. Also, thermo regulator y functional clothes are frequently used as underwear and sweat shirt. The consumer awareness investigation on thermo regulatory functional clothing showed that the most important key buying factor is quick climate temperature response, easy maintenance, design and cost, in that order. Surface temperature of garment went down with the cooling down of environmental temperature. The lower environmental temperature, the greater temperature difference by body part showed. Skin temperature change by environmental temperature showed similar tendency of garment surface temperature. In comparison between garment surface and body skin, temperature difference became larger under the lower environmental temperature.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.7
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• pp.567-575
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• 2014

This paper suggests an installation procedure of a smart skin prototype into an aircraft, flight demonstration test procedures and test results. Four communication and navigation antennas are embedded into one Conformal Load-bearing Antenna Structure(CLAS). Log periodic patch type antenna was designed as a multi-band antenna to cover four antenna frequency bands. The requirements of CLAS were verified by ground tests before aircraft installation. A CLAS speed-brake was installed into KT-1 aircraft and performances of dual antennas were verified as multi-antenna tests on the ground. Electromagnetic compatibility tests were conducted to check compatibility between the CLAS and all existing equipments. Flight demonstration tests were conducted by one sortie of flight test for one antenna. The activeness and continuity of communication and navigation signal during the flight, null area of antenna signal along the circling flight were monitored. The embedded antennas worked better than expected during four sorties of flight tests.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.6
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• pp.551-557
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• 2013

In intelligent robot research, hand gesture recognition has been an important issue. And techniques that recognize simple gestures are commercialized in smart phone, smart TV for swiping screen or volume control. For gesture recognition, robust hand detection is important and necessary but it is challenging because hand shape is complex and hard to be detected in cluttered background, variant illumination. In this paper, we propose efficient hand detection algorithm for detecting pointing hand for recognition of place where user pointed. To minimize false detections, ROIs are generated within the compact search region using skin color detection result. The ROIs are verified by HOG-SVM and pointing direction is computed by both detection results of head-shoulder and hand. In experiment, it is shown that proposed method shows good performance for hand detection.

• Journal of the Korean Applied Science and Technology
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• v.40 no.2
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• pp.258-267
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• 2023

In this study, to investigate the possibility of using ethanol extract of Petasites japonicus (PJE) as a functional material, we investigated the activity of improving skin barrier and inflammation through UVB-induced human keratinocyte (HaCaT cell). As a result of confirming the antioxidant effect through DPPH radical scavenging activity, ABTS⁺ radical scavenging activity, and hydrogen peroxide scavenging activity, it was confirmed that it had an antioxidant effect similar to that of ascorbic acid, a control, at a concentration of 1 mg/ml. As a result of confirming the mRNA expression of the production ability of filaggrin and aquaporin-3 in HaCaT cells induced by UVB, it was confirmed that the reduced expression level by UVB stimulation increased in a concentration-dependent manner when the PJE was treated. It was confirmed that the mRNA expression of TNF-𝛼 and IL-1𝛽 were increased by UVB stimulation and decreased when the PJE was treated. As a result of the migration assay, it was confirmed that the proliferation of skin keratinocytes and the recovery rate of wounds were increased in a concentration-dependent manner. Based on the experimental results, it suggests that Petasites japonicus can be used as a functional cosmetic product that can improve skin moisturizing and skin barrier function.

• Tribology and Lubricants
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• v.33 no.4
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• pp.148-152
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• 2017

The feel of writing is important to customers when they buy smart devices with stylus such as smartphones and tablet computers. With an aim to reproduce the tactile sensibility of writing instruments when people write on the glass display using a stylus, this study focuses on the frequency characteristics of writing instruments that can describe the vibrations of writing instruments sliding over counter surfaces. In addition, this study includes the effect of various factors influencing the friction of writing instruments such as lubricant, nib material, and contact type. We perform sliding experiments with six types of writing instruments and a sheet of paper to understand the relation between the friction conditions of the nib and the frequency characteristics. As this research focuses on the tactile perception of human skin when people use a writing instrument, the analysis of frequency characteristics is performed in the perceptible frequency range of mechanoreceptors in the human skin. As a result, three types of frequency characteristics are identified. Low frequency peaks are observed for a metal nib with ink; high frequency peaks are observed for a nib without ink; and, middle frequency peaks with a wide range of distribution occurs for fabric nibs with ink. Therefore, to implement the proper feel of writing, at least three types of vibrations have to be made.