• International journal of advanced smart convergence
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• v.10 no.4
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• pp.30-37
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• 2021

Touch sensor interface has become the most useful input device in a smartphone. Unlike keypad/keyboard interfaces used in electronic dictionaries and feature phones, smartphone's touch interfaces allow for the recognition of various gestures that represent distinct features of each application's input. In this paper, we analyze application-specific input patterns that appear in smartphone's touch interfaces. Specifically, we capture touch input patterns from various Android applications, and analyze them. Based on this analysis, we observe a certain unique characteristics of application's touch input patterns. This can be utilized in various useful areas like user authentications, prevention of executing application by illegal users, or digital forensic based on logged touch patterns.

• Journal of the Ergonomics Society of Korea
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• v.23 no.2
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• pp.105-120
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• 2004

With the new technology and the popularization of mobile phone. the functions and designs of mobile phone have been varied rapidly. However. based on the user's level of familiarity on mobile phone function and knowledge of information technology. the using behaviors of mobile phone. especially between the young users who are well acquainted with the latest function and technology and the over middle-aged users who are relatively not. would be quite different. A survey was conducted to investigate the various using behaviors of mobile phone in different age groups. The total number of six hundred and sixty-seven people from age seventeen to sixty participated in this study. The participants were divided into young group (age between 17 to 29) and the over middle-aged group (age between 40 to 60) to compare the difference group considered design. price. and function of the mobile phone as three important factors. on the other hand. the over middle-aged group considered quality of communication. price and ease of use as three important factors. All the respondents of the young group know how to use the text messaging function. however for the over middle-aged group. 40% of the respondents knows how to use the text messaging function. The over middle-aged group seemed mainly use the mobile phone for voice communication. however the young group had a tendency to communicate each other with short text message rather than through voice conversation. Twenty percentage of young group responded that they had an experience of pain or discomfort at the thumb. the thenar eminence area. or carpus area during pushing the mobile phone keypad. The excessive frequent use of keypad may cause the risk of repetitive strain injury (RSI). The results of this study could provide important information to understand the way of using mobile phone in different age groups. and also could be used to design and market the mobile phone.

• Journal of the Korea Convergence Society
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• v.8 no.6
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• pp.37-44
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• 2017

Mobile devices provide various services through payment and authentication by inputting important information such as passwords on the screen with the virtual keypads. In order to infer the password inputted by the user, the attacker captures the user's touch location information. The attacker is able to infer the password by using the location information or to obtain password information by peeping with Google Glass or Shoulder Surfing Attack. As existing secure keypads place the same letters in a set order except for few keys, considering handy input, they are vulnerable to attacks from Google Glass and Shoulder Surfing Attack. Secure keypads are able to improve security by rearranging various shapes and locations. In this paper, we propose secure keypads that generates 13 different shapes and sizes of Tetris and arranges keypads to be attached one another. Since the keypad arranges different shapes and sizes like the game, Tetris, for the virtual keypad to be different, it is difficult to infer the inputted password because of changes in size even though the attacker knows the touch location information.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.493-495
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• 2005

제한된 휴대폰 자판에서 효율적인 한글 입력을 위한 방법으로서 본 논문에서는 고정적인 한글 자소의 버튼 배치를 하지 않고, 사용자가 입력하는 한글의 상태에 따라 동적으로 변하는 S/W 자판을 제안한다. 이와 동시에 방향키와 숫자키의 동시 사용 가능한 입력 방식을 제안함으로써 기존의 휴대폰 한글 입력 방식이 가지는 다양한 문제점을 해결하였다.

• 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 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.

• Journal of KIISE:Software and Applications
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• v.35 no.12
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• pp.780-788
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• 2008

Modeling hand poses and tracking its movement are one of the challenging problems in computer vision. There are two typical approaches for the reconstruction of hand poses in 3D, depending on the number of cameras from which images are captured. One is to capture images from multiple cameras or a stereo camera. The other is to capture images from a single camera. The former approach is relatively limited, because of the environmental constraints for setting up multiple cameras. In this paper we propose a method of reconstructing 3D hand poses from a 2D input image sequence captured from a single camera by means of Belief Propagation in a graphical model and recognizing a finger clicking motion using a hidden Markov model. We define a graphical model with hidden nodes representing joints of a hand, and observable nodes with the features extracted from a 2D input image sequence. To track hand poses in 3D, we use a Belief Propagation algorithm, which provides a robust and unified framework for inference in a graphical model. From the estimated 3D hand pose we extract the information for each finger's motion, which is then fed into a hidden Markov model. To recognize natural finger actions, we consider the movements of all the fingers to recognize a single finger's action. We applied the proposed method to a virtual keypad system and the result showed a high recognition rate of 94.66% with 300 test data.

• Science of Emotion and Sensibility
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• v.11 no.4
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• pp.575-588
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• 2008

This study is to inquire respective patterns of mental models caused by wrongful usages which can be experienced when a user who is used to a keypad-based mobile phone starts using a touch screen mobile phone and to find out the features of the user's logical process of correcting such wrongful usages to a new mental model. In addition, design improvement to be considered for easy generation of the mental model regarding touch screen mobile phones was reviewed in this study. We set up test subjects for the most frequently used seven high priority functions among touch screen phone functions and carried out the subject assessment together with interview surveys after the video observation experiment. Our test results show that test subjects who were used to keypad-based mobile phones tend to use operation knowledge related to the computer operational system(Window) or the web browse, navigation including Tap or Double Tap in order to correct the mental model when a wrongful usage is made. In addition, the result of comparison and analysis of the subject assessment and the video observation experiment data shows that wrongful usages of touch screen mobile phones mostly occurred in the field of 'information feedback' and 'navigation' among mobile phone components.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.9-14
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• 2015

Touch interface is widely used in a smartphone instead of a keyboard or a keypad interface that has been adopted in a PC or a featurephone, respectively. Touch interface can recognize a variety of gestures that clearly represent the distinct features of each application's input. This paper analyzes users' gesture of each application captured by the touch interface of a smartphone. Specifically, we extract touch input traces from various application categories such as game, web browser, youtube, image and e-book viewer, video player, camera, and map applications, and then analyzed them. Through this analysis, we observed a certain unique characteristics of each application's touch input, and this can be utilized in various useful areas such as identification of an application user, prevention of running an application by an illegal user, or design of a new interface convenient to a specific user.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.5
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• pp.622-629
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• 2019

VR(Virtual Reality), which provides realistic services in virtual reality, provides a similar experience using a Head Mounted Display(HMD) device. When the HMD device is worn, it can not recognize the surrounding environment and it is easy to analyze the input pattern of the user with the Shoulder Surfing Attack(SSA) when entering the Personal Identification Number(PIN). In this paper, we propose a method to safeguard the user's password even if the hacker analyzes the input pattern while maintaining the user's convenience. For the first time, we implemented a new type of virtual keypad that deviates from the existing rectangle shape according to the VR characteristics and implemented the lock object for intuitive interaction with the user. In addition, a smart glove using the same sensor as the existing input devices of the VR and a PIN input method suitable for the rotary type are implemented and the safety of the SSA is verified through experiments.