• Journal of the Korean Society for Precision Engineering
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• v.21 no.10
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• pp.94-101
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• 2004

This paper presents the development of a keypad test system for the improvement of working environment and productivity using PTC 16F877 microprocessor. In order to detect the fault of keypad products, hardware and software design is performed in this system. Keypad fault detection system is controlled by the 8 bit one chip PIC microcontroller for the exactness and speed. Developed panel of the keypad test system is comprised of the sub-panel for selecting in the inspected keypad types and the main panel f3r displaying the working order and fault position. Furthermore, all data from keypad inspection are stored in main memory of personal computer for the database. All these functions lead to the improvement of working speed and environment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.459-462
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• 2002

This paper presents the development or a keypad test system for the improvement or the working environment and productivity improvement using the microprocessor PIC16F877 Chip. In order to detect the fault of keypad products, the design of hardware and software is performed in this system. All controls of the system is implemented by the 8 bit one chip micro-controller PIC. This keypad test system can also recognizes the work process, the work result and the fault position of the keypad which is made by the method of a flexible printed circuit (FPC) and construct the database about test results using personal computer. The experimental results show the effective performance of the keypad test system.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.544-547
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• 2008

As the mobile electronic product is getting slimmer and smaller, the necessity of keypad is being increased. But the possibility of mis-typing keypad is increased rapidly due to the integrated keypad in the small mobile product. The business division has not considered the methodology of keypad design essentially. In this paper, analysis method and design evaluation standard to reduce the mis-typing of UMPC(Ultra Mobile Personal Computer) is suggested. First, the finite element analysis model and the biomechanical human body model are implemented in order to simulate the exact contact characteristic between finger and keypad. The reliability of analysis model is guaranteed by the comparison of the contact pressure between analysis result and experiment result of the pressure sensor. The design optimization of key shape and layout is derived through the response surface method. The prototype model is produced with the optimized design of keypad, and then it verified the advanced function with user mis-typing detection test. The optimized keypad design reduced the mis-typing ratio from 35% of existing model to 75 of proposed model. If this paper is widely applied to not only UMPC but also the other electronic products, the emotional quality of all products could be improved considerably.

• Design & Manufacturing
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• v.11 no.1
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• pp.34-38
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• 2017

Deformation frequently occurring in injection molded products is a phenomenon displayed due to uneven shrinkage distribution and orientation of the whole molded product. Shrinkage deformation is a very serious problem because it causes deformation of the molded article and shortens the performance of the product. In this paper, we are focusing on the warpage of keypad in mobile phone. In other words, we focused on minimizing keypad deformation. In the study, the Taguchi method was applied to find the injection molding conditions that minimize the deformation of the keypad. In the case of this keypad, the main factors influencing the shrinkage deformation were predicted as the melting temperature, coolant temperature and cooling time. In addition, the optimum molding conditions were obtained and the shrinkage strain was minimized. Experiments for the Taguchi method and verification of optimal molding conditions were performed using an injection molding analysis program.

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.3
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• pp.73-80
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• 2018

Due to the popularity of smartphones and the simplification of financial services, the number of mobile financial services is increasing. However, the security keypads developed for existing financial services are susceptible to probability analysis attacks and have security vulnerabilities. In this paper, we propose and implement a security keypad based on dual touch. Prior to the proposal, we examined the existing types of security keypads used in the mobile banking and mobile payment systems of Korean mobile financial businesses and analyzed the vulnerabilities. In addition, we compared the security of the proposed dual touch keypad as well as existing keypads using the authentication framework and the existing keypad attack types (Brute Force Attack, Smudge Attack, Key Logging Attack, and Shoulder Surfing Attack, Joseph Bonneau). Based on the results, we can confirm that the proposed security keypad with dual touch presented in this paper shows a high level of security. The security keypad with dual touch can provide more secure financial services, and it can be applied to other mobile services to enhance their security.

• Journal of Internet Computing and Services
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• v.22 no.4
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• pp.29-49
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• 2021

This paper proposes the Hunminjungum Keypad that applied the creation principle of Hunminjungum to the design of keypad. The proposed keypad arranged 28 letters of Hunminjungum to have correlations with each other between consonants, between vowels, and between consonants and vowels. That is, Consonant buttons are arranged by grouping letters of the same sound by sounds of five voices. And the vowel buttons are arranged at the bottom and the right side of the consonant area according to the position where a vowel is attached to the consonant. In the meantime, Hangul keypads have mainly used 12 button keypads in 4 lines and 3 columns. These keypads have structurally disadvantageous in the touch count and moving distance. Recently, keypads with many letter buttons such as QWERTY and single-vowel are also used a lot. If the number of letter buttons provided in the keypad increases, touch count decreases. And If the letter buttons are arranged to have a correlation with each other, the moving distance becomes smaller. The experimental results show that the proposed keypad has high efficiency in all evaluation factors such as touch count, moving distance and input time.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.6
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• pp.814-820
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• 2009

The arrangement of the general 12-button cellular phone keypad is unified with one or two kind. In general, the several alphabets are arranged in one key. When inputting an English, countries which do not speak English use multi-tap method. We can input next alphabet by pressing key repeatedly. We address the problem of finding multi-tap-based keypad designs which minimize the number of key presses for various case. Genetic algorithms is proposed method for optimal keypad designs. We are to maintain the number of keys, which is ranged from 8 to 12. We also show experimental using non-alphabetically-constrained and alphabetically-constrained arrangement, respectively. Finally, we give improved keypad designs.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.821-823
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• 1999

This paper describes a study on a person identification system which can improve currently available biometric systems. In the procedure of PIN(Personal Identification Number) input, holding time, interkey time between key presses are measured and normalized. Person identification is performed by matching using Euclidean distance of these punching dynamics. The experimental results show the possibility of improvement of the overall system performance when keypad dynamics feature is applied to the biometric systems which take PIN input using keypads.

• Journal of Korean Electronics
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• v.2 no.8
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• pp.24-31
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• 1982

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.469-471
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• 2004

기존의 전화기 자판은 여러 번의 키 누름에 의해 입력해야 하는 숨겨진 자음과 모음의 배열 때문에 문자 입력에 많은 불편이 따른다. 본 논문에서는 보다 쉬운 한글 입력을 위해서 휴대용 전화기의 키패드(Keypad)에 대한 분산형 한글 자판 배열과 그 자판 배열을 이용해서 쉽게 한글 문자를 입력할 수 있는 사용자 중심의 대화형 방법을 제시한다. 모든 단자음과 단모음이 키에 나타나 보이도록 중복 할당시키고 입력하고자 하는 글자를 구성하는 자소를 필기순서에 따라 해당키를 한번씩만 눌러서 입력할 수 있도록 했다. 또한 복자음이나 복모음의 입력을 글자의 필기 순서와 동일하게 입력하도록 하여 사용자의 문자 입력에 대한 부담이 최소화 되도록 했다. 모의실험을 통하여 기존의 방식보다 입력에 필요한 키 동작의 횟수가 줄었음을 확인했다.