• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.5
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• pp.659-665
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• 2011

Recently, the plastic resin such as PC, ABS are widely used in IT market. Especially, in most cases the keypads mounted on the mobile phone are the dual-injection-plated type. Environmental regulation is based on the quality of injection-molded products and the minimum process steps are required to avoid the plating defects. Various parameters to produce the injection-molded plastic products make it difficult to obtain the desired stability. However, the past experience and the use of CAE analysis make it possible to predict the problems occurred in injection molding process. Especially, the problems of the weld lines such as runner balancing, bending, deformation and forming defects can be solved systematically and minimized by CAE analysis. Through this study, the non-uniform volumetric shrinkage and the difference in temperature distribution induce the deformation and the high value of stress causes the problems such as crack.

• The Journal of the Acoustical Society of Korea
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• v.17 no.1
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• pp.60-65
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• 1998

전화기의 선택 및 제어 신호는 직류 임펄스의 수에 의한 방법을 사용하였으나 현재 는 복합 주파수 방식을 널리 사용하고 있으며, 음성을 이용한 서비스들도 복합 주파수 방식 에 의해 제공되고 있다. 본 논문에서는 전화기의 복합 주파수 신호를 한글 자소로 변환하는 번호판 매핑 방법을 제시하였으며, 이 방식을 이용하여 상용되는 음성 정보 서비스의 검색 코드 입력 방식을 재구성해 보았다. 즉, 여러 가지 서비스에서도 한글 문장을 사용할 수 있 음을 보였다. 또한, 전화 통화시 사용되는 문장을 번호판 매핑 방식을 적용하여 구성함으로 써 전화기에서의 문장 편집 및 문장 정보 교환의 가능성을 보였다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.151-162
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• 1990

Occupational disease among typists such as Carpal Tunnel Syndrome(CTS) and tendonitis has increased along with rapid expansion of office automation. During typing, the posture can be defined as forearm pronation, ulnar abduction, wrist extension and finger flexion. The CTS results from awkward posture between forearm-wrist-hand and the keyboard arrangement. Therefore, ergonomic principles should be emphasized in keyboard design. The objective of the study is to improve keyboard design by analyzing anatomical posture of forearm and hand during typing. An experimental study was performed to investigate relationships between a keyboard and typing performance. Results showed that typing performance is dependent to angles and slopes of a keyboard. Statistical analysis indicated that the suggested ergonomic keyboard improved typing speed significantly(17%).

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.424-427
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• 1997

Electrical impedance plethysmography is still be one of the simplest and most convenient methods or non-invasive measurement of blood low, but it has the weak point can not do real-time measurement because of using chart-record or processing after receiving data from analog plethysmography through A/D converter. In this study. we developed hardware system composed of analog part which include auto-balancing circuit and calibration register and digital part which include 80C196KC, keypad, and LCD. we studied the algorithms or extracting parameter to calculate blood low and implemented it using general purpose micro controller.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.313-314
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• 2006

Indicating product quantity by real time can be benefit both worker and management. Worker can compare real product quantity with its target and can adjust working speed to match with goal. Therefore, so called JPH equipment developed to indicate target quantity of product. As a main processor PIC16F877 was used and FND display were used to indicate current time, elapsed time, JPH value and target amount of product. Values like JPH and starting time, etc. are can easily be set by $4{\times}4$ numeric keypad and display datum likes target amount of product, current time and elapsed time, etc are displayed on FND by RS232 serial transmit. The operation of JPH equipment are tested and verified through long term test and are proved acting properly on working conditions.

• Journal of the Ergonomics Society of Korea
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• v.24 no.1
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• pp.47-53
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• 2005

The purpose of this study was to evaluate performance and subjective satisfaction of mobile phone's interface elements considering the elderly users. First, mobile phone's interface elements were outlined recent foreign and domestic studies. Then, final three mobile phone's interface elements were determined by expert rating, AHP analysis, and questionnaire analysis. Objective and subjective measures were then used to determine the effects of several specific design parameters and aging differences on performance of mobile phones. In this experiment, 38 subjects and 4 independent variables were used to measure task completion time and user's subjective satisfaction. The statistical analyses indicated significant aging differences between older people and younger people in terms of keypad type and bell sound level in performance. Significant aging differences were also found for user subjective satisfaction. It is suggested that some major results from this study be used to develop mobile phone design guidelines that are more usable and accessible for most users, particularly for older users.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.875-876
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• 2006

In this paper, we propose a multimodal biometric embedded system. It is designed to support face, iris, fingerprint and vascular pattern recognition. We use a S3C2440A based on ARM926T core processor that is made in Samsung. The system has support various external device interfaces for multi biometric sensors, and RFID/Smart Card reader/writer. Additionally, it has a 6" LCD panel and numeric keypad for easy GUI. The embedded system offers useful environments to develop better biometric algorithms for stand alone biometric system and accelerator hardware modules for real time operation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.766-768
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• 2016

Conventional locking device has a disadvantage such as a security vulnerability caused by using avoid traces of the keypad that are frequently used due to the complex password application. In this study, we proposed a OTP based locks by using user identical informations that overcomes the disadvantages of the conventional apparatus. We implemented and validated the proposed algorithm through simulations.

• Journal of the Semiconductor & Display Technology
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• v.13 no.4
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• pp.77-81
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• 2014

There have been developed in authentication systems for information using biometric information approaches such as fingerprint, face, and iris. In general, a door-lock system is operated by touching keypads, which remains fingerprints on the keypads. Such door-lock systems do not protect personal information from others due to the exposure of fingerprints to keypads. In this paper, we propose the new door-lock system that does not leave fingerprints on the keypads. Without touching keypad the system works because the system accepts authentication information by using illuminance sensor and LED. The experiment shows that the implemented door-lock system works well under any circumstance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.435-440
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• 2011

A touchless user interface system is proposed for real-time mobile devices in this work. The proposed system first recognizes the position of pattern to interact various applications based on the scene taken from mobile camera. Then, the proposed system traces the route of the pattern, which estimates the motion of pattern based on the mean-shift method. Based on this information, we control menu and keypad for the various applications. Differ from other user interface systems, the proposed system provides the new experience to even for the user of low-end mobile without additional hardware. Simulation results demonstrate that the proposed algorithm provides better interaction performances than the conventional method, while achieving real-time user interacting for mobile devices.