• Proceedings of the Korean Information Science Society Conference
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• 2011.06a
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• pp.202-205
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• 2011

최근 들어 스마트폰 시장이 활성화 되면서 휴대기기용 플랫폼인 안드로이드 역시 각광받고 있다. 오픈 플랫폼인 안드로이드에 수많은 제조사들과 개발자들이 가세하면서 다양한 플랫폼 버전이 탑재된 하드웨어가 출시되고 있다. 이처럼 혼재된 안드로이드 환경 때문에 상호호환성 문제와 함께 그에 따른 테스트의 필요성 또한 대두되고 있는 상황이다. 하지만 기존의 연구들은 테스트 케이스 자동 생성에 주로 초점이 맞추어져 있고, 컴파일 및 실행에 있어서 반복적인 작업이 필요한 안드로이드의 특성을 반영하지 못하고 있어 테스트 과정에 과도한 시간이 소모되고 인력 및 비용 또한 손실되고 있다. 이에 본 논문에서는 안드로이드 기반 소프트웨어 테스트 시 고려해야 할 문제점을 분석하여 비효율적인 면을 제거하고 테스트를 자동으로 진행할 수 있는 테스트 자동화 체계를 제안한다. 이를 통해 기존의 테스트 과정에서 과하게 투입되는 시간, 인력 및 비용을 줄이고 개발 기간이 짧은 안드로이드 소프트웨어 마켓 시장에 효율적으로 대응할 수 있는 이점을 얻을 수 있다.

• Journal of Korea Multimedia Society
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• v.11 no.5
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• pp.641-650
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• 2008

As portable devices are used widely, power management algorithm is essential to extend battery use time on small-sized battery power. Although many methods have been proposed, they assumed the voltage transition overhead was negligible or was considered partially. However, the voltage transition overhead might not guarantee to schedule real-time tasks in portable multimedia systems. This paper proposes the adaptive power-aware algorithm to minimize the power consumption by considering the voltage transition overhead. It selects only a few discrete frequencies from the whole frequencies of a system and adjusts the interval between two consecutive frequencies based on the system utilization to reduce the number of frequency change. This algorithm saves the power consumption about 10 to 25 percent compared to a CC RT-DVS method and a frequency-smoothing method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.194-195
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• 2006

개인 휴대 통신 기기의 급속한 발달로 인해 부품의 소형화, 고집적화가 중요한 요소로 대두되고 있으며 이를 위해서는 모듈내부에 3차원적인 수동소자의 내장이 가능한 LTCC (Low Temperature Co-fired Ceramics) 공정이 각광받고 있다. Embedded Capacitor를 제조하기 위해 유전율이 7.6과 6.5인 LTCC 재료를 이종접합 하여 제조하였으며 이종재료의 수축거동 차이에 의한 camber가 발생하였다. 이를 해결하고 또한 고주파 부품용 정밀회로 패턴을 구 현하기 위해 PLAS 방식의 Constrained Sintering 공정을 적용하여 camber 문제를 해결하였으며 capacitance 값이 두 이종재료의 유전율과 1:1로 비례하지 않았는데 이는 유전율 65 tape에 잔존하는 기공 때문으로 판단되며 미세구조로써 확인하였다.

• 한국정보교육학회:학술대회논문집
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• 2011.01a
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• pp.59-65
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• 2011

The purpose of this paper is to develop an application that utilizes educational tools on the Smart-Phone, which will make it possible for student education in any environment. Strengths that a Smart-Phone application has include always being carried by the student, short boot time to open the program and rather than having to use a traditional computer for access. Tests can be taken repeatedly, so students prepare before class and keep their motivation level high, thus raising overall test outcomes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.6
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• pp.1391-1396
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• 2010

Recently, communication components prefer Bluetooth or Zigbee for PAN. However, using these makes expensive and complicated products such as audio equipments, mobile phones, PC, etc. for transmitting simple messages with low rate. In this paper, we propose wireless communication method using ultrasonic in the audio frequency limit band with speakers and microphones which are in products. We suggest transmitting and receiving methods in the audio frequency limit band for transmitting data without affecting audio signal, and implement an ultrasonic communication modem. Finally, we verify the performance of the ultrasonic communication modem by experiments in an environment with background noise.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.8
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• pp.722-730
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• 2014

Due to the advance of hardware, various devices have mobility features, and many applications need the data transmission. In addition, it is essential for latest smartphones to utilize multi-cores and multi-threads because of the enhancement of Application Processor. Therefore, this paper analyzes the performance/power consumption according to transmission rate, the number of cores, and that of threads in the system that is supposed to conduct data transmission and processing simultaneously. Through the analysis, this paper provides a direction for the proper number of threads in terms of performance improvement and efficient power consumption.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1633-1638
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• 2013

The mobile phone has now evolved into an effective multimedia devices to watch video content with your PC in addition to the calling features. Thus, the effectiveness of the video content streaming services smartphone will be available. And content should be able to deliver effectively. Be provided with textbook images and video of the speaker means that the effective content delivery. In this paper, we propose a integrated video management system that can be real-time VOD services on the Internet as input Multi-Source of audio-video, video content encoding system to meet the requirements of the above two.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.830-832
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• 2013

The mobile phone has now evolved into an effective multimedia devices to watch video content with your PC in addition to the calling features. Thus, the effectiveness of the video content streaming services smartphone will be available. And content should be able to deliver effectively. Be provided with textbook images and video of the speaker means that the effective content delivery. In this paper, we propose a integrated video management system that can be real-time VOD services on the Internet as input Multi-Source of audio-video, video content encoding system to meet the requirements of the above two.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.2
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• pp.187-193
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• 2004

For a power source of usual electronic devices such as PDA, smart phone, UPS and electric vehicle, the battery made of serially connected multiple cells is generally used. In this case, if there are some unbalanced among cell voltages, the total lifetime and the total capacity of the battery are limited to a lower value. To maintain a balanced condition in cells, an effective method of regulating the cell voltage in indispensable. In this paper, we propose the design of a balancing circuit for electronic appliances. The balancing system was controlled by a micro-controller which enables to implement the balancing action during charging period. Proposed method has been verified by the experiment using the charger and recorder. The experimental results show that the individual battery equalization can improve battery capacity and battery lifetime and performance through an extended operational time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.1B
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• pp.9-18
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• 2006

Advances in wireless network are enabling the development of ubiquitous multimedia services. These multimedia services need efficient platforms to comply with the requirements of mobile computing. We introduce an adaptive service platform based on mobile agent and grid systems while specifying the challenges of ubiquitous multimedia services and focusing on frequent disconnections and scarce resources. We applied our platform to framework RtoA (Ready-to-Attend) which supports mobile users to access compute-intensive multimedia service, specifically, mobile education and video conferencing. RtoA includes hand-off, speaker and listener service which enable people to attend a conference or a class with satisfying quality of multimedia service. ns-2 based simulation verifies that our scheme is an efficient way to reduce energy consumption of mobile devices and to improve the response time of mobile applications.