• The Journal of Korean Association of Computer Education
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• v.5 no.4
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• pp.79-89
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• 2002

Several multi-user online applications which are operated by the existing fixed terminals(PC) are being changed into online application based on multi-platform operated by the several PC, PDA and mobile phones to perform concurrent works recently. The contents of current online application based multi-platform are, however, very unsophisticated because the applications don't consider the simultaneous accesses of shared data by multi-user and also the asymmetry of computing power and network bandwidth among each client. This paper proposed the methods of consistency control based on multi-platform, update propagation protocols among diverse clients, object management techniques which take the characteristics of mobile clients into account. We also implemented a chatting application based on multi-platform and it showed the proposed methods perform well.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.37-44
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• 2006

본 연구는 모바일기기 사용자들의 특성을 알아보고자 사용자들의 모바일기기 휴대의도에 영향을 미치는 변수들을 기준으로 사용자들을 세분화 하였다. 선행문헌연구를 통해 휴대의도에 영향을 미치는 변수들로 유용성, 즐거움, 불안감과 사회적 영향인 주관적 규범, 가시성, 이미지, 자발성 등을 도출하였다. 자료수집을 위해 서울 및 수도권에 거주하고 휴대폰이나 노트북, PDA등을 소유한 대학생 및 대학원생과 직장인들을 대상으로 설문조사를 실시하였다. 휴대의도의 영향변수 분석결과 불안감과 주관적 규범이 휴대의도에 유의한 양의 영향을 미치는 것으로 검증되었다. 이를 기준변수로 군집분석을 통해 전체 표본을 네 집단으로 세분화 하였다. 세분화 결과 군집 1은 주관적 규범만이 영향을 미치는 집단으로 전체응답의 36.25%를 차지하고 있으며, 군집 2는 불안감만이 영향을 미치는 집단으로 전체 응답의 13.44%를 구성하는 것으로 나타났다. 군집 3은 불안감과 주관적 규범 모두 영향을 미치지 않는 집단으로서 전체 응답에서 19.06%를 차지하고 마지막으로 군집 4는 불안감과 주관적 규범 모두 영향을 미치는 집단으로 전체응답의 31.25%를 구성하는 것으로 나타났다.

• Journal of the Korea Society of Computer and Information
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• v.17 no.7
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• pp.13-22
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• 2012

In this paper, we design and implement the architecture of the ubiquitous software robot platform (Sobot platform) based on Web 2.0. In order to provide a user with the personalized emotional service by transferring to any device without any time or geographical limitations, the software robot must be developed as a form of a platform based on the standardized data and structures. To verify the effectiveness and the feasibility of the proposed Sobot platform consisting of the terminal platform, the server platform, and the contents composer, we compose user-created emotional Sobot contents messages on heterogeneous platforms such as PC, a mobile phone, a PDA, and a web portal site and experiment a variety of Sobot transfer implementation between them.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.2
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• pp.61-68
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• 2010

As a result of the growth of mobile devices such as PDA and cellular phone, a user can utilize various digital contents everywhere and anytime. However, mobile devices have the limited resources and interaction mechanisms. This paper introduces the schema for a user activity estimation and its application in order to overcome the poor user interface and limited resource problems. We are able to supplement lacking the user interface of mobile devices by using the user activity estimation proposed in this paper, and its application is a intelligent control interface for the display power on or off which can effectively utility the battery of the mobile device.

• Journal of the Korea Society of Computer and Information
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• v.11 no.1 s.39
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• pp.167-176
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• 2006

In this paper, a home network access agent, which controls and monitors networked appliances at home using various terminals regardless of user's location, is designed and implemented. The proposed access agent integrates wire and wireless network on a home gateway (or home server) and is accessed with consistent messages using various terminals such as a web terminal, a PDA and a cellular phone. Also, in order to verify the operation and availability of the agent, a user interface for the various terminals is designed and a home network testbed which is accessed and controlled by the terminals is implemented.

• The Journal of Korean Association of Computer Education
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• v.6 no.4
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• pp.49-59
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• 2003

In order to index exactly moving objects(vehicle, mobile phone, PDA, etc.) in a mobile database, continuous updates of their locations arc inevitable as well as time-consuming. In this paper, we propose a spatial indexing method of moving objects for the efficient mobile map services. In detail, we analyze the characteristics of both the method to re-index all the objects after each time period and the method to update immediately the locations on reporting their locations. We also newly propose a bucket split method using the properties of moving objects in order to minimize the number of database updates. The experiments conducted on the environments of moving object show that the proposed indexing method is appropriate to map services for mobile devices.

• 전자공학회논문지 IE
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• v.47 no.3
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• pp.14-18
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• 2010

In this paper, we describe a CMOS DC-DC converter with a variable output voltage(5-7V @100mA) for a portable battery-operated system applications. The proposed DC-DC converter is used along with a Pulse-Frequency Modulation (PFM) method and consists of reference circuit, a feedback resistor, a controller, and an internal oscillator. The integrated DC-DC converter with two external passive components(L,C) has been designed and fabricated on a 0.5um 2-poly 3-metal CMOS process and could be applied to the Personal Digital Assistants(PDA), cellular Phone, Laptop Computer, etc.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.677-681
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• 2002

Several multi-user online applications which are operated by the existing fixed terminals(PC) are being changed into online application based on multi-platform operated by the several PC, PDA and mobile phones to perform concurrent works due to the popularization of mobile devices recently. This paper proposed the infrastructure for network applications based on multi-platform. We also proposed the methods of consistency control based on multi-platform, update propagation protocols among diverse clients which take the asymmetry of computing power and network bandwidth among each client into account. Moreover, we implemented a chatting application based on multi-platform and it showed the proposed infrastructure and methods perform well.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.1-10
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• 2007

Many types of information provided through the web including news contents contain unnecessary clutters. These clutters make it difficult to build automated information processing systems such as the summarization, extraction and retrieval of documents. We propose a system that extracts and summarizes news contents from the web. The extraction system receives news contents in HTML as input and builds an element tree similar to DOM tree, and extracts texts while removing clutters with the hyperlink attribute in the HTML tag from the element tree. Texts extracted through the extraction system are transferred to the summarization system, which extracts key sentences from the texts. We implement the summarization system using co-occurrence relation graph. The summarized sentences of this paper are expected to be transmissible to PDA or cellular phone by message services such as SMS.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.6
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• pp.82-92
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• 2001

This paper describes implementation of an embedded 32-Bit RISC core for portable communication/information equipment, such as cellular phones, PDA(Personal Digital Assistants), notebook, etc. The RISC core implements the ARM$\circled$V 4 instruction set, operates with typical 5-stage pipeline. It supports Thumb code to improve the code density, and uses the dynamic power management method of pipeline registers. It was modeled and simulated in RTL level using VHDL, and verified with ARMulator of ADS (Arm Developer Suite) and had average CPI of 1.44. The core is synthesized automatically using the cell library based on $0.6{\mu}m$ CMOS 1-poly 3-metal CMOS technology. It consists of about 41,000 gates and the clock frequency is expected to be above 45 MHz.