• Journal of the Korea Institute of Information Security & Cryptology
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• v.11 no.2
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• pp.73-82
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• 2001

In this paper we propose an efficient authentication and key agreement protocol which has been designed specifically for use with low powered computationally weak equipment such as Cellular phone and PDA(Personal Digital Assistant). Imple-menting the protocol based on the Rabin cryptosystem provides the efficiency requirements for mobile communications including minimum number of passes and low computational lead. The paper outlines the new protocol, examines it s various aspects, and compares them to those representative authentication and key agreement protocols.

• Journal of Advanced Navigation Technology
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• v.11 no.1
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• pp.72-78
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• 2007

In this paper, the wide-band monopole antenna with a parasitic element on the ground plane for application in Cellular, GSM and RFID mobile terminals such as the mobile phone or Personal Digital Assistant(PDA) phone is presented. The VSWR of the designed antenna is 2:1 over the frequency range of 820 MHz to 1040 MHz(bandwidth of 23.6 %). Therefore, the designed antenna can provide wide bandwidth covering the Cellular(824 MHz~894 MHz), RFID(908.5 MHz~914 MHz) and GSM(Tx:880 MHz~915 MHz, Rx:925 MHz~960 MHz). The radiation characteristics of the fabricated antenna were also studied. According to the measured radiation patterns, the maximum gains at 859 MHz and 911.25 MHz(center frequencies of the Cellualr and RFID bands) are -0.7 dBi and 0.16 dBi, respectively. The measured maximum gains of GSM bands are -0.48 dBi(897.5 MHz, the center frequency of Tx) and 1.69 dBi(942.5 MHz, the center frequency of Rx).

• The KIPS Transactions:PartD
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• v.10D no.6
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• pp.1033-1040
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• 2003

In order to provode information services on M-Commerce, a payment solution with security function should be required. User's mobile terminals for using M-Commerce services are diversifying to cellular phone, PDA, Smart phone etc. Among them, intergration of PDA's interface and mobile connection overcomes the weak point of existing cullular phone depending on information via the internet. In this paper, the protocol for a credit card transaction on PDA using ECC is presented. Secure Card module on this protocol encrypts user's information such as private information, delivery information and credit card information and store them on PDA in order to free from inputting information whenever it is used. This scheme also offers security services on M-Commerce including authentication, confidentiality, integration, non-repudiation and so on.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.933-936
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• 2008

Mobile devices such as cellular phones and PDA become a part of our life by extreme improvement of Wireless internet and arriving the age of Ubiquitous. Especially it makes increasing rapidly the expectations about a field of remote control that is great advantage of Mobile devices. Existing computer remote control systems are hard to meet user's appropriate manage when error happened because Clients could not recognize the state of several remote controlled computers which connected to web server. This paper Implementation remote computer control system that immediately after errors happen by send error massages in the from of a SMS to client by set the clients with cellular phone that most generally used Mobile devices.

• Journal of Digital Contents Society
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• v.8 no.1
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• pp.17-25
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• 2007

Recently, the ubiquitous computing environment being able to connect all kinds of computing elements at anytime anywhere becomes widespread in human life. In this paper, we focus on a PC remote control system using cellular phones. Especially, we design and implement an mobile e-mail transmission system using PC remote control technique. By using our remote controller, cellular phone users can login into their own PC, and then send any file to others by e-mail attachment. To show the correct running of our system, real demonstration results are presented. We are sure that by opening our source code to the public our results can play an important role to encourage development of the various mobile remote control functionalities.

• Journal of Science and Technology Studies
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• v.1 no.1 s.1
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• pp.179-200
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• 2001

In this study, the conceptual model which can integrate the social process and technological teaming in technological innovation is developed and applied to the analysis of the cases on the innovation of Korean mobile telecommunication industry. Korean mobile telecommunication Industry has two peculiar characteristics. First, there have been rapid technological loaming and catching-up processes in Korean mobile telecommunication which have never been in other newly industrializing countries. Second, CDMA is the only multiple access mode which has been used in cellular phone service. It is the purpose of this study to analyse how these characteristics have been emerged during past ten years based on the suggested model integrating the social process of technology selection and technological learning.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.7 s.184
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• pp.130-137
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• 2006

TFT-LCD(Thin Film Transistor Liquid Crystal Display) module is representative commercial product of FPD(Flat Panel Display). Thickness of TFT-LCD module is very thin. It is adopted for major display unit for IT devices such as Cellular Phone, Camcorder, Digital camera and etc. Due to the harsh user environment of mobile IT devices, it requires complicated structure and tight assembly. And user requirements for the mechanical functionalities of TFT-LCD module become more strict. However, TFT-LCD module is normally weak to high level transient mechanical shock. Since it uses thin crystallized panel. Therefore, anti-shock performance is classified as one of the most important design specifications. Traditionally, the product reliability against mechanical shock is confirmed by empirical method in the design-prototype-drop/impact test-redesign paradigm. The method is time-consuming and expensive process. It lacks scientific insight and quantitative evaluation. In this article, a systematic design evaluation of TFT-LCD module for mobile IT devices is presented with combinations of FEA and testing to support the optimal shock proof display design procedure.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.3
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• pp.289-300
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• 2010

Recently, diverse information which are location, call history, SMS history, photographs, and video can be collected constantly from mobile devices such as cellular phone, smart phone, and PDA. There are many researchers who study services for searching and abstraction of personal daily life with contextual information in mobile environment. In this paper, we introduce MyLifeBrowser which is developed in our previous work. Also, we explain LPS and correction of GPS coordinates as extensions of previous work and show LPS performance test and evaluate the performance of expanded keywords. MyLifeBrowser which provides searching personal information in mobile device and support of detecting related information according to a fragmentary keyword and common knowledge in ConceptNet. It supports the functionality of searching related locations using Bayesian network that is designed by the authors. In our experiment, we visualize real data through MyLifeBrowser and show the feasibility of LPS server and expanded keywords using both Bayesian network and ConceptNet.

• The KIPS Transactions:PartA
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• v.9A no.4
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• pp.467-478
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• 2002

With the rapid development of wired or wireless Internet, various kinds of resource constrained mobile devices, such as cellular phone, PDA, homepad, smart phone, handhold PC, and so on, have been emerging into personal or commercial usages. Most software to be embedded into those devices has been forced to have the characteristic of flexibility rather than the fixedness which was an inherent property of embedded system. It means that recent technologies require the flexible embedding into the variety of resource constrained mobile devices. A document processor for XML which has been positioned as a standard mark-up language for information representation on the Web, is one of the essential software to be embedded into those devices for browsing the information. In this paper, a framework for configurable XML processor called EmXJ is designed and implemented for flexible embedding into various types of resource constrained mobile devices, and its advantages are compared to conventional XML processors.

• IE interfaces
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• v.22 no.1
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• pp.17-25
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• 2009

In mobile device's user interface, menu organization is very important as well as menu structure because small display of mobile device. Menu items should be organized based on user knowledge structure to design user-centered interface. Traditionally, MDS (Multidimensional Scaling) have been most often used to expose users' perceived organization of menu items. But, information that MDS reveals is just relative spatial location of concepts and not relevant to concepts connection. Unlike MDS, Trajectory Mapping explicitly finds users' cognitive links between perceived concepts. This study proposes a Trajectory Mapping technique for eliciting knowledge structure, especially a set of cognitive pathways linking menu items, from end user. With twelve participants, MDS and Trajectory Mapping were conducted using cellular phone's menu items. And user knowledge structure was analyzed through Visual Concept Map that combination of results of MDS and Trajectory Mapping. After then, menu items were organized according to users' perceived organization. Empirical usability test was also conducted. The results of usability test showed that usability, in terms of task performance time, number of errors, and satisfaction, for newly organized interface was significantly improved compare to original interface. The methodology of this study is expected to be applicable to design a user-centered interface. In other words, Trajectory Mapping technique can be used as a design tool of user interface for imposing user knowledge structure on the interface.