• Journal of the Korea Convergence Society
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• v.8 no.2
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• pp.9-14
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• 2017

A fingerprint is unique to each person and can be represented as a digital form. As the fingerprint is the part of human body, fingerprint recognition is much more easy to use and secure rather than using password or resident card for user authentication. In addition, as the newly released smart phones have built-in camera and fingerprint sensors, the demand for biometric authentication is increasing rapidly. But, the drawback is that the fingerprint can be counterfeited easily and if it's exposed to the hacker, it cannot be reused. Thus, the original fingerprint template should be transformed for registration and authentication purposes. Existing transformation functions use passcode to transform the original template to the cancelable form. Additional module is needed to input the passcode, so it requires more cost and lowers the usability. In this paper, we propose biometric authentication scheme that is economic and easy to use. The proposed scheme is consisted of cancelable biometric template creation, registration and user authentication protocols, and can control several security levels by configuring the number of fingerprints and scan times. We also analyzed that our scheme is secure against the brute-force attack and the active attacks.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.3
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• pp.193-200
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• 2006

This paper suggests a 6-pulse-shift converter structure with PWM current-source inverter based on buck-boost configuration to improve the efficiency and to reduce the switching frequency of inverter for photovoltaic generation system, the device can be operated as interface system between solar module system and power system grid without energy storage cell. The circuit has six current-source buck-boost converter which operate chopper part and kas one full bridge inverter which make a decision the polarity of AC output. Therefore, the proposed PWM power inverter has advantages such as the reduction of witching loss and realization of unity power factor operation. The theoretical backgrounds are discussed and the input-output characteristics for the implemented prototype inverter using TMS320F2812 are verified experimentally in this paper.

• Journal of the Korea Furniture Society
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• v.21 no.5
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• pp.380-391
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• 2010

Modular furniture's colors, materials, finishing materials and quantities are determined by users' tastes and it's diverse functions, shapes and sizes are determined by the spaces of users. That is, modules satisfy the diversity of consumers, meet differentiated individuals' tastes and enable communications with consumers rather than delivering one-way messages of designers. The contemporary spaces of the 21st century have been gradually shifting from uniform spaces attaching weight on individuals' individuality and tastes and along with it, the consumption of expensive custom-made furniture and foreign branded furniture is increasing to satisfy those small numbers of consumers who want to express diversified individuality. The modular furniture as a concept which is the most suitable to Mass Customization can be produced in large quantities while considering the diverse needs and tastes of individuals and it does not have absolute shapes or sizes. The concept of modular furniture shows similarities to the creation of fractals that forms shapes by self similarities, repeats and similar transformations which is in the same context as the characteristics of a modular design that presents diversity with scales, materials and jointing points. Fractals will be combined with the digital media of today to present great plasticity and influence designers more heavily. Pursuit of new modeling is a requisite for the creation of future spaces and it will require continuous creativity and the transformable modular furniture will contribute to the satisfaction of diverse consumers' needs. This study is to propose the modular furniture that considers the diversity of the public in the 21st century and their individuality and that will enable interactions between designers and consumers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.5113-5119
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• 2010

Anthropometry has been broadly explored in various fields including automobile industry, home electronic appliances, medical appliances and sports goods with aiming at reaching satisfaction to consumer's need and efficiency. However, current technologies to measure a human body still have barriers in which the methods mostly seem to be contingent on expensive devices such as scanner and digital measuring instruments and to be directly touchable to the body when obtaining body size.. Therefore, in this paper, we present a general method to automatically extract size of body from a real body image acquired from a camera and to utilize it into recommend systems including clothing and bicycle fitting. At first, Haar-like features and AdaBoost algorithm are employed to detect body position. Then features of body can be recognized using AAM. Finally clothing and bicycle recommending modules have been implemented and experimented to validate the proposed method.

• Transactions on Electrical and Electronic Materials
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• v.14 no.1
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• pp.47-51
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• 2013

A high power MOSFET switch based on a 0.35 ${\mu}m$ CMOS process has been developed for the protection IC of a rechargeable battery. In this process, a vertical double diffused MOS (VDMOS) using 3 ${\mu}m$-thick epi-taxy layer is integrated with a Zener diode. The p-n+Zener diode is fabricated on top of the VDMOS and used to protect the VDMOS from high voltage switching and electrostatic discharge voltage. A fully integrated digital circuit with power devices has also been developed for a rechargeable battery. The experiment indicates that both breakdown voltage and leakage current depend on the doping concentration of the Zener diode. The dependency of the breakdown voltage on doping concentration is in a trade-off relationship with that of the leakage current. The breakdown voltage is obtained to exceed 14 V and the leakage current is controlled under 0.5 ${\mu}A$. The proposed integrated module with the application of the power MOSFET indicates the high performance of the protection IC, where the overcharge delay time and detection voltage are controlled within 1.1 s and 4.2 V, respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.4
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• pp.1024-1030
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• 2015

Safety and security system have been internationally enhanced in a field of shipping logistics. Accordingly, techniques for safety and security have been studied steadily. The need of portable radiation detection device is increasing by the search of the container is enhanced. In this paper, we propose a study to improve the life of the system and the realization of portable radiation detection device based on Cortex-A9. Configuration of a portable radiation detection device is configured largely to an analog board and the digital platform and the sensor module. The power used in each stage of the analog board is varied. Uses a switching regulator to use various power supply thereby to generate an error result and cause the switching noise. It is proposed to reduce the power consumption reducing technique for the study.

• Journal of Environmental Impact Assessment
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• v.8 no.4
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• pp.1-12
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• 1999

The purpose of this study is to develop a Water Quality Management System(WQMS), which calculates pollutant discharge and forecasts water quality with a water pollution model. Operational water quality management requires not only controlling pollutants but acquiring and managing exact information. A GIS software, ArcView 3.1 was used to enter or edit geographic data and attribute data, and Avenue Script was used to customize the user interface. PCI, a remote sensing software, was used to derive land cover classification from 20 m resolution SPOT data by image processing. WQMS has two subsystems, database subsystem and modelling subsystem. The database subsystem consisted of watershed data from digital maps, remote sensing data, government reports, census data and so on. The modelling subsystem consisted of NSPLM(NonStorm Pollutant Load Model) and SPLM(Storm Pollutant Load Model). It calculates the amount of pollutant and predicts water quality. These two subsystems were connected through a graphic display module. This system has been calibrated for and applied to Mokhyun Stream watershed.

• Journal of Biomedical Engineering Research
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• v.29 no.6
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• pp.443-450
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• 2008

The purpose of this study is to measure both ECG and BCG(Ballistocariograph) signal of a subject on moving or resting wheelchair and detect the heart rate and respiratory rate and transmit an event message to remote server on emergent situation. To acquire ECG and BCG data, amplifier circuits were composed to be suitable for their characteristics. The output signals were converted to digital data and stored in bio-signal archiving media(SD card). CDMA module was used to transmit the event data on ECG electrode detachment and the received data was monitored by the developed C# application program. 5 volunteers participated in the experiment to evaluate the validity of the developed device. When the event occurs in each subject, 48 Kbyte data, stored for 32 seconds from that point, was transmitted to remote server through CDMA cellular phone network correctly. The received data of ECG, BCG, and 3-axial acceleration could be archived in server and the heart rate and respiratory rate could be measured and analyzed. The developed device in this study could acquire the ECG and BCG data of subjects on wheelchair simultaneously and measure their heart rate and respiratory rate. In addition, event data was verified to be transmitted to remote server without any errors.

• Journal of Biomedical Engineering Research
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• v.35 no.6
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• pp.203-210
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• 2014

Wearable medical device has been a resurgence of interest thanks to the development of technology and propagation of smart phone in recent years. Various types of wearable devices have been introduced and available in market. Capacitive coupled electrode which measures electrocardiogram over cloth is able to be applied wearable device. In previous approaches of capacitive electrode, they need proper pressure for stable contact of the electrode to body surface. However, wearable device that gives pressure on body surface is not suitable for long-term monitoring. In this study, we proposed adhesive polyurethane-based capacitive electrode for patch-type wearable electrocardiogram (ECG) monitoring device. Self-adhesive polyurethane make the electrode and whole system be adhered to the surface of skin without any pressure. The patch-type system is consisted of analog filter, analog-to-digital converter and wireless transmission module and designed to be attached on the body as a patch. To validate the feasibility of the developed system, we measured ECG signal in stable and active state and extracted heart rate. Therefore, we observed skin response after long-term attachment for biocompatibility of the adhesive polyurethane and adhesive strength of it. The result shows the possibility of applying the developed system for ECG monitoring in real-life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.443-448
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• 2010

Rapid advance in information technology requires high performance devices with compact size. Integrated multi-layer electronic element with different functions enables those compact devices to possess various performances and powerful capabilities. In mass production, the multi-layer electronic element is manufactured as a bulk type with a large number of parts for productivity. However, this may cause the electronic part to be damaged in the cutting process of the bulk elements to separate into each part. Therefore the cutting performance of multi-layer element bulk is playing an important role in the view of production efficiency. This study focuses on the cutting characteristics of multi-layer electronic elements. In order to increase the efficiency, the vibration cutting method was applied to the blade cutting machine. Flexure hinge structure, which is an physical amplifier of increasing displacement, was attached to the vibration cutting device for machining efficiency. The behaviors of flexure hinge were modeled with Lagrange equation and simulated with finite element method (FEM). Performance of hinge structure was verified by experimental modal analysis (EMA) for hinge structure to be tuned to the specific mode of vibrations. Cutting experiments of multi-layer elements were conducted with the proposed vibrating cutting module, and the characteristics was analyzed.