• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1913-1914
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• 2006

Modem Industrial control systems tend to adopt a variety of intelligent wireless device controllers to interface front-end computers with active components of the industrial device. Some of the intelligent control systems come equipped with a wireless SMS(Simple Message Service) interface giving an opportunity to use fault alarm Interlock system. Immediately send warning or alert messages to Mobile devices or remote users. Real time monitoring the SMS systems by Mobile devices. Control systems remotely by mobile devices in emergency situation. In order to provide against system fault, SMS Mobile System will enable system administrator to promptly access, monitor and control the system whenever users want and wherever users are, by utilizing wireless Internet and mobile devices. This paper presents the Mobile SMS system for PAL Control System.

• 디지털산업정보학회논문지
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• 제8권1호
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• pp.99-105
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• 2012

Given the numbers of smartphones, tablets and other mobile devices shipped every day, more and more users are relying on the cloud as the main driver for satisfying their computing needs, whether it is data storage, applications or infrastructure. Mobile cloud computing is simply cloud computing in which at least some of the devices involved are mobile. Each node is owned by a different user and is likely to be mobile. Using mobile hardware for cloud computing has advantages over using traditional hardware. These advantage include computational access to multimedia and sensor data without the need for large network transfer, more efficient access to data stored on other mobile devices and distributed ownership and maintenance of hardware. It is important to predict job execution time in mobile cloud computing because there are many mobile nodes with different capabilities. This paper analyzes the job execution time for mobile cloud computing in terms of network environment and heterogeneous mobile nodes using a mathematical model.

• 한국정보과학회논문지:정보통신
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• 제32권6호
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• pp.651-658
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• 2005

모바일 장치의 사용이 대중화되면서 무선 통신을 이용한 화상회의, 다중 사용자 게임, 인터랙티브 채팅 등의 그룹 기반의 어플리케이션에 대한 관심이 증가되고 있다. 이러한 그룹 기반의 어플리케이션이 안전하게 수행되기 위해서는 그룹 구성원간 안전한 통신을 위한 키 동의가 선행되어야 한다. 기존에 제안된 모바일 환경에서의 그룹키 동의 프로토콜에서는 하나의 셀 내의 모바일 장치들이 그룹키를 공유하는 것을 고려하였다. 본 논문에서는 기존 모델을 확장하여 최초로 서로 다른 셀에 속한 모바일 장치들 간의 그룹키 동의 프로토콜을 제안하고 안전성을 분석하도록 한다. 또한 모바일 장치의 계산 부담을 줄이기 위해 패스워드 인증 방식을 제안한 프로토콜에 적용해 보도록 한다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제11권2호
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• pp.157-164
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• 2005

무선 인터넷 기술과 모바일 컴퓨팅 기술의 발달로, M-Commerce가 PDA나 모바일 폰 등과같은 다양한 무선 장치상에서 실현되고 있다. 현재 M-Commerce를 위한 상품 컨텐츠는 목표 무선 장치의 특징을 충족할 수 있도록 새롭게 작성되고 있다. 이것은 자원의 중복이며, 자원 관리에 엄청난 노력이 요구된다. 따라서 현재 I-Commerce를 위해서 제공되고 있는 인터넷 상품 정보를 효과적으로 이용하는 것이 필요하다. 그러나 이러한 이용에는 적은 메모리 용량, 작은 디스플레이 화면, 낮은 수행속도 등의 모바일 장치의 많은 제약성이 고려되어야 한다. 본 논문에서는 모바일 폰 상에 인터넷 XML 상품 문서를 효과적으로 이용하기 위해 클라이언트에서 문서에 대한 객체계층구조를 구성하는 4가지 방법을 제안하고, 실험을 통해서 사용자 응답시간과 메모리 사용량 관점에서 비교, 분석한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권1호
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• pp.25-44
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• 2010

With the increasing popularity of mobile devices, it has become necessary to protect private information and content in these devices. Face recognition has been favored over conventional passwords or security keys, because it can be easily implemented using a built-in camera, while providing user convenience. However, because mobile devices can be used both indoors and outdoors, there can be many illumination changes, which can reduce the accuracy of face recognition. Therefore, we propose a new face recognition method on a mobile device robust to illumination variations. This research makes the following four original contributions. First, we compared the performance of face recognition with illumination variations on mobile devices for several illumination normalization procedures suitable for mobile devices with low processing power. These include the Retinex filter, histogram equalization and histogram stretching. Second, we compared the performance for global and local methods of face recognition such as PCA (Principal Component Analysis), LNMF (Local Non-negative Matrix Factorization) and LBP (Local Binary Pattern) using an integer-based kernel suitable for mobile devices having low processing power. Third, the characteristics of each method according to the illumination va iations are analyzed. Fourth, we use two matching scores for several methods of illumination normalization, Retinex and histogram stretching, which show the best and $2^{nd}$ best performances, respectively. These are used as the inputs of an SVM (Support Vector Machine) classifier, which can increase the accuracy of face recognition. Experimental results with two databases (data collected by a mobile device and the AR database) showed that the accuracy of face recognition achieved by the proposed method was superior to that of other methods.

• 디지털융복합연구
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• 제9권4호
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• pp.1-8
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• 2011

모바일 기기란 터치 입력을 가진 표시 화면과 소형 자판을 가진 작은 크기기의 컴퓨팅 장치로 이동성과 편리함을 갖추고 인터넷 접속이 가능한 기기로 정의된다. 모바일 기기는 혁신 제품이므로 소비자들은 기술수용 문제와 구매를 위한 의사결정 문제에 직면하게 된다. 본 연구에서는 모바일 기기 구매 의사결정 지원방법의 하나로 계층적분석과정 방법을 제안한다. 6개 주기준과 15개의 세부기준으로 구성된 계층적 모델을 제안하고, 다수의 의사결정자가 참여할 때 평가기준의 중요도와 4개의 모바일 기기(넷북, 테블릿 PC, 카메라폰, 스마트폰)의 우선순위를 도출하는 방법을 제안하였다. 평가기준 중 휴대성이 가장 중요도가 높은 것으로 나타났다. 평가 대안 중 스마트폰의 우선순위가 가장 높았지만 전반적으로 모바일 기기 간 선호도는 차이가 없었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.193-195
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• 2004

This paper presents a novel data transmit method using display units of mobile devices. Mobile devices such as personal-digital-assistants (PDAs) and cellular phones have a display unit. The typical display unit is a liquid-crystal-display (LCD) with an back-light. Since the proposed data transmit method uses the LCD or back-light as a data transmitter, it is a kind of sightable light communication. Tn order to transmit the data, the display unit drived by an application program on the platform of mobile devices. In this paper, detailed data transmit scheme, specific data protocol are presented and discussed. Finally, with the experimental results, usefulness of the proposed data transmit method is verified.

• 한국멀티미디어학회논문지
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• 제7권12호
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• pp.1754-1764
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• 2004

Lately mobile handheld devices such as Personal Digital Assistant (PDA) and cellular phones are getting more popular for personal web surfing. However, today most mobile handheld devices have relatively poor web browsing capability due to their low performance so their users have to suffer longer communication latency than those of desktop Personal Computers (PCs). In this paper, we propose an effective pre-refresh mechanism for embedded web browser of mobile handheld devices to reduce this problem. The proposed mechanism uses the idle time to pre-refresh the expired web objects in an embedded web browser's cache memory. It increases the utilization of Central Processing Unit (CPU) power and network bandwidth during the idle time and consequently reduces the client's latency and web browsing cost. An experiment was done using a simulator designed by us to evaluate the efficacy of the proposed mechanism. The experiment result demonstrates that it has a good performance to make web surfing faster.

• Journal of Information Processing Systems
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• 제14권5호
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• pp.1272-1285
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• 2018

The paper presents a novel embedded multifunctional media sever (EMMS) for mobile devices to receive various media programs. Being different from other contemporary system research, the paper mainly studies how to design a reception solution for terrestrial digital television (DTV) on mobile devices and how to enable mobile devices can receive DTV program, enjoy video-on-demand (VOD), achieve video surveillance and relay Internet video program via local Wi-Fi simultaneously. In the system design, we integrate broadcasting-terrestrial DTV tuner, streaming media re-transmission system, VOD disk, video camera and access interface to the Internet into EMMS, which can either receive terrestrial DTV radio signals and demodulate out digital transport stream (TS), or can read streaming media bit-stream from VOD disk, surveillance camera or access interface to the Internet. The experimental results show the proposed system is stable and quality-efficient. Comparing with the other systems, the proposed system has the least packet loss rate and response time.

• Journal of Computing Science and Engineering
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• 제9권3호
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• pp.155-162
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• 2015

The last decade has seen a rapid growth in the use of mobile devices all over the world. With an increasing use of mobile devices, mobile applications are becoming more diverse and complex, demanding more computational resources. However, mobile devices are typically resource-limited (i.e., a slower-speed CPU, a smaller memory) due to a variety of reasons. Mobile users will be capable of running applications with heavy computation if they can offload some of their computations to other places, such as a desktop or server machines. However, mobile users are typically subject to dynamically changing network environments, particularly, due to user mobility. This makes it hard to choose good offloading decisions in mobile environments. In general, users' mobility can provide some hints for upcoming changes to network environments. Motivated by this, we propose a mobility model of each individual user taking advantage of the regularity of his/her mobility pattern, and develop an offloading decision-making technique based on the mobility model. We evaluate our technique through trace-based simulation with real log data traces from 14 Android users. Our evaluation results show that the proposed technique can help boost the performance of mobile devices in terms of response time and energy consumption, when users are highly mobile.