• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.265-273
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• 2011

Objective: The aim of this study is to investigate the attributing factors influencing usability of the mobile phones specifically designed for the elderly users. Efforts to identify factors that cause usability problems for the elderly users in using mobile phones can provide the groundwork for changes aimed at usability enhancement and design of interfaces of mobile phones. Background: It became important to understand the behaviors and tendencies of the elderly in communication as the society became older. The problems in digital divide is contributed to mainly lack of understanding in terms of the use pattern of the elderly and lack of consideration of their characteristics in designing user interfaces of most ICT devices. Method: A total of 30 elderly users who were over 65 years in age participated in usability evaluation test experiment and performed seven different tasks using a widely accepted model of universally designed mobile phone. Their performance was compared with that of contrast group that consisted of 10 younger participants who were on their 20s. Results: It was found that the elderly users had hard times in using mobile phones, especially in keypad manipulation among search, understanding, and manipulation subtasks. Conclusion: Older users seemed to have difficulty in all the subtasks of search, recognition, and manipulation. It was suggested that designers of mobile phones need to give careful consideration into designing visual interfaces for search tasks and keypads for easier control and input for the elderly users. Application: The study is expected to provide guidelines for the universal design of mobile phones and their interfaces for enhancing usability of the mobile phone for elderly users.

• Journal of Preventive Medicine and Public Health
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• v.37 no.4
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• pp.373-380
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• 2004

Objectives : There has been gradually increasing concern about the adverse health effects of electromagnetic radiation originating from cell phones which are widely used in modern life. Cell phone radiation may affect human health by increasing free radicals of human blood cells. This study has been designed to identify DNA damage of blood cells by electromagnetic radiation caused by cell phone use. Methods : This study investigated the health effect of acute exposure to commercially available cell phones on certain parameters such as an indicator of DNA damage for 14 healthy adult volunteers. Each volunteer during the experiment talked over the cell phone with the keypad facing the right side of the face for 4 hours. The single cell gel electrophoresis assay (Comet assay), which is very sensitive in detecting the presence of DNA strand-breaks and alkali-labile damage in individual cells, was used to assess peripheral blood cells (T-cells, B-cells, granulocytes) from volunteers before and after exposure to cell phone radiation. The parameters of Comet assay measured were Olive Tail Moment and Tail DNA %. Results : The Olive Tail Moment of B-cells and granulocytes and Tail DNA % of B-cells and granulocytes were increased by a statistically significant extent after 4-hour use of a cell phone compared with controls. Conclusion : It is concluded that cell phone radiation caused the DNA damage during the 4 hours of experimental condition. Nonetheless, this study suggested that cell phone use may increase DNA damage by electromagnetic radiation and other contributing factors.

• The KIPS Transactions:PartB
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• v.14B no.5
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• pp.391-400
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• 2007

An interactive Hangul input method using the numeric phone keypad, which is applicable for mobile devices is introduced. In the proposed method, user only selects the corresponding keys by single tapping, for the alphabet of Korean letter which is desired to enter. The interface generates the subset of eligible letters for the key sequence, then the user selects the desired letter in the set. Such an interactive approach transforms the text entry interface into a multi-level interactive letter-oriented style, from the preexisting passive and single-level alphabet-oriented interface. The annoyance of key-operations, the major disadvantage of the previous methods, derived from multi-tap to clear the ambiguity of multi-assigned alphabets for the Hangul automata, can be eliminated permanently, while the additional letter selection procedure to finalize the desired letter is essential. Also the complexity of Hangul text entry is reduced since all letters can be compounded from basic alphabet selection of the writing sequence order. The advantage and disadvantage of the proposed method are analyzed through comparing with pre-existing method by experiments.

• 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.

• 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 Korea Information Processing Society Conference
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• 2004.05a
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• pp.659-662
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• 2004

이동통신용 전화기의 숫자 자판에서 다수의 한글 자소가 한 개의 키에 할당되기 때문에 한글 입력에 많은 번거로움이 따른다. 본 논문에서는 이러한 번거로움을 최소화 하기위해서 모든 단자음과 단모음이 키에 모두 표시되도록 설계한 분산형 한글 자판 배열과 글자를 구성하는 자소를 필기순서에 따라 해당키를 한번씩만 눌러서 입력할 수 있도록 하는 사용자 중심의 새로운 한글 입력 방식을 제안한다. 다양한 실험을 통해서 제안된 방법이 기존의 방식들에 비해서 키누름 동작에 따르는 입력 효율이 높은 것을 확인했다.

• Archives of design research
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• v.17 no.3
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• pp.441-448
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• 2004

Mobile devices such as mobile phones or PDAs are considered as main interlace tools in ubiquitous computing environment. For searching information in mobile device, it should be possible for user to input some text as well as to control cursor for navigation. So, we should find efficient interlace method for text input in limited dimension of mobile devices. This study intends to suggest a new approach to mobile interaction using camera based virtual keyboard for text input in mobile devices. We developed a camera based virtual keyboard prototype using a PC camera and a small size LCD display. User can move the prototype in the air to control the cursor over keyboard layout in screen and input text by pressing a button. The new interaction method in this study is evaluated as competitive compared to mobile phone keypad in left input efficiency. And the new method can be operated by one hand and make it possible to design smaller device by eliminating keyboard part. The new interaction method can be applied to text input method for mobile devices requiring especially small dimension. And this method can be modified to selection and navigation method for wireless internet contents on small screen devices.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.1
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• pp.177-185
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• 2016

As the fintech industry is growing at an incredible rate, mobile phones are positioned as the most important tool for financial transaction. However, with a rising number of malware applications, the types of attack and illegal access to mobile device are becoming more diverse and sophisticated. This paper studies the potential keylogger attack by exploiting the Accessibility Service in Android framework. This type of attack allows the malicious individual to use keylogger on the victim's Android mobile phone to steal passwords during mobile financial transaction regardless of security keypad setting. Lastly the paper proposes solutions to counter these types of attack by verifying the accessibility usage and amending the application guideline for accessibility.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.39-47
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• 2008

With dramatic development of IT technology and start of DMB service, installing the DMB equipment in a vehicle for watching TV programs and literal or pictorial traffic information are increasing. Watching the DMB during driving the vehicle could cause visual and cognitive distraction to drivers as much as eating food, operating radio and using mobile phone. However, there is not much empirical research for this topic and no research examined the effect of watching the DMB on driving behaviors in Korea. So, the present study examined the effect of watching the DMB on the driving behaviors with car simulator experiment. Within subject design was used in the study. That is, all subjects drove the vehicle both in the watching DMB condition and the non-watching DMB condition. The results indicated that subjects in the watching DMB condition took longer time to arrive at the destination and operated accelerator and brake pedal rapidly than subjects in the non-watching DMB condition. That is, their overall driving stability was lower than non-watching subjects'. Additionally, we examined the difference among the DMB control conditions (i.e., keypad condition, touch-pad condition and remote controller condition) in the driving behaviors. Finally, we discussed the limitations and the implications of the present study.