• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.66-75
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• 2010

We proposed an occupant sensing system using single video camera and ultrasonic sensor for the advanced airbag. To detect the occupant form and the face position in real-time, we used the skin color and motion information. We made the candidate face block image using the threshold value of the color difference signal corresponding to skin color and difference value of current image and previous image of luminance signal to gel motion information. And then it detects the face by the morphology and the labeling. In case of night without color and luminance information, it detects the face by using the threshold value of the luminance signal get by infra-red LED instead of the color difference signal. To evaluate the performance of the proposed occupant detection system, it performed various experiments through the setting of the IEEE camera, ultrasonic sensor, and infra-red LED in vehicle jig.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.8
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• pp.683-688
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• 2014

This paper presents a high-performance flexible tactile sensor based on inorganic silicon flexible electronics. We created 100 nm-thick semiconducting silicon ribbons equally distributed with 1 mm spacing and $8{\times}8$ arrays to sense the pressure distribution with high-sensitivity and repeatability. The organic silicon rubber substrate was used as a spring material to achieve both of mechanical flexibility and robustness. A thin copper layer was deposited and patterned on top of the pressure sensing layer to create a flexible temperature sensing layer. The fabricated tactile sensor was tested through a series of experiments. The results showed that the tactile sensor is capable of measuring pressure and temperature simultaneously and independently with high precision.

• Smart Structures and Systems
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• v.8 no.1
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• pp.93-105
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• 2011

This paper presents a flexible low-profile antenna sensor for fatigue crack detection and monitoring. The sensor was inspired by the sense of pain in bio-systems as a protection mechanism. Because the antenna sensor does not need wiring for power supply or data transmission, it is an ideal candidate as sensing elements for the implementation of engineering sensor skins with a dense sensor distribution. Based on the principle of microstrip patch antenna, the antenna sensor is essentially an electromagnetic cavity that radiates at certain resonant frequencies. By implementing a metallic structure as the ground plane of the antenna sensor, crack development in the metallic structure due to fatigue loading can be detected from the resonant frequency shift of the antenna sensor. A monostatic microwave radar system was developed to interrogate the antenna sensor remotely. Fabrication and characterization of the antenna sensor for crack monitoring as well as the implementation of the remote interrogation system are presented.

• Current Optics and Photonics
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• v.4 no.4
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• pp.368-372
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• 2020

We report the terahertz time-domain spectroscopy (THz-TDS) of transdermal drug delivery in human skin. The time evolution of transdermal nicotine delivery in nicotine patches was assessed by detecting the transmission coefficient of sub-picosecond THz pulses and using a semi-analytic model based on the single-layer effective medium approximation. Using commercial nicotine patches (Nicoderm CQ^®, 7 mg/24 h), THz transmission coefficients were measured to quantitatively analyze the cumulative amounts of nicotine released from the patches in the absence of their detailed specifications, including multilayer structures and optical properties at THz frequencies. The results agreed well with measurements by conventional in vitro and in vivo methods, using a diffusion cell with high-performance liquid chromatography and blood sampling respectively. Our study revealed the ability of the THz-TDS method to be an effective alternative to existing methods for noninvasive and label-free assessments of transdermal drug delivery, showing its high promise for biomedical, pharmaceutical, and cosmetic applications.

• Journal of Information Processing Systems
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• v.14 no.2
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• pp.435-447
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• 2018

Fingerprint-based biometric identification is one of the most interesting automatic systems for identifying individuals. Owing to the poor sensing environment and poor quality of skin, biometrics remains a challenging problem. The main contribution of this paper is to propose a new approach to recognizing a person's fingerprint using the fingerprint's local characteristics. The proposed approach introduces the barycenter notion applied to triangles formed by the Delaunay triangulation once the extraction of minutiae is achieved. This ensures the exact location of similar triangles generated by the Delaunay triangulation in the recognition process. The results of an experiment conducted on a challenging public database (i.e., FVC2004) show significant improvement with regard to fingerprint identification compared to simple Delaunay triangulation, and the obtained results are very encouraging.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.223-227
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• 2003

A new flexible electronic packaging technology and its medical applications are presented. Conventional silicon chips and electronic modules can be considered as "mechanically rigid box." which does not bend due to external forces. This mechanically rigid characteristic prohibits its applications to wearable systems or bio-implantable devices. Using current MEMS (Microelectromechanical Systems) technology. a surface micromachined flexible polysilicon sensor array and flexible electrode array fer neural interface were fabricated. A chemical thinning technique has been developed to realize flexible silicon chip. To combine these techniques will result in a realization of truly flexible sensing modules. which are suitable for many medical applications.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.2
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• pp.66-75
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• 1993

This paper proposes a monitoring method for nondestructive and in-process measurement of the case depth in LASER surface heat treatment process. The method is essentially an eddy-current method, and measures sensing coil's electrical impedance which varies with the changes of the material microstructure due to hardening. To investigate te validity of the proposed method a series of experiments were performed for various hardning depths. The results show that the relationship between the eddy- current sensor output and the changes in case depth is almost linear. This indicates that the eddy-current measuring method can be used as one of the possible monitoring method for mesauring the hardened depth in LASER heat treatment processes.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.51-63
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• 2017

The touch panel was developed decades ago and has become a popular input device in daily life. Because human-computer interaction is becoming more important, the next generation of touch panels require stretchability and bio-compatibility to allow integration with the human body. However, because most touch panels were developed based on stiff, brittle electrodes, electronic touch panels face difficulties to achieve such requirements. In this paper, for the first time, we demonstrate an ionic touch panel based on polyacrylamide hydrogel containing LiCl ions. The panel is soft and stretchable and thus, can sustain a large deformation. The panel can freely transmit light information through it because the hydrogel is transparent, with 99 % transmittance for visible light. A 1-dimensional touch strip was investigated to reveal the basic mechanism of sensing, and a 2-dimensional touch panel was developed to demonstrate its functionalities. The ionic touch panel was operated under high deformation with more than 1000% areal strain without sacrificing its functionalities. Furthermore, an epidermal touch panel on the skin was developed to demonstrate the mechanical and optical invisibility of the ionic touch panel through writing words, playing the piano and playing games.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1272-1274
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• 1996

This paper presents the development of tactile sensor systems for robot hand which are truly usable, robust, reliable and cheap system. The sensor incorporates multiple sensing subsystems for detecting distributed contact forces and surface characteristics. The fabrication and experimental evaluation of the tactile system and its electric interfaces are described. The results indicate that the system provides reasonable performances for practical applications requiring manipulation with tactile feedback.

• Electronics and Telecommunications Trends
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• v.34 no.1
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• pp.86-97
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• 2019

Over the past 30 years, significant developments have been made in hyperspectral imaging (HSI) technologies that can provide end users with rich spectral, spatial, and temporal information. Owing to the advances in miniaturization, cost reduction, real-time processing, and analytical methods, HSI technologies have a wide range of applications from remote-sensing to healthcare, military, and the environment. In this study, we focus on the latest trends of HSI technologies, analytical methods, and their applications. In particular, improved machine learning techniques, such as deep learning, allows the full use of HSI technologies in classification, clustering, and spectral mixture algorithms. Finally, we describe the status of HSI technology development for skin diagnostics.