• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.287-290
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• 2010

최근 기기간의 접속에 적합한 근거리 무선 접속기술의 요구가 증대됨에 따라, 그 요구에 대응하는 무선통신기술의 하나로 UWB(Ultra Wide Band)가 주목을 받고 있다. 특히, TV와 캠코더, 카메라 등의 AV기기 상호 간의 무선접속을 포함하여 PC나 휴대정보단말(PDA) 등이 네트워크에 무선으로 접속하는데 UWB 기술은 주요한 역할을 담당할 것으로 예상된다. 최근 서비스가 진행되고 있는 HDTV를 비롯하여 향후 UHDTV(Ultra-HDTV) 등의 방송시스템이 본격화되면 HD급 이상의 캠코더는 고해상도에 따른 대용량 데이터를 저장하고 AV기기 간의 데이터 전송을 위해 고속 무선 데이터 전송이 필수적이다. 또한 이와 같은 고속 무선데이터 전송을 위해서는 보다 안정된 송수신 기술이 절대적으로 필요하다. 이를 위하여 본 논문에서는 차세대 UWB의 설계 제약조건 중 하나인 저전력 송신환경에서 수신 신뢰도의 향상을 이루기 위해 LDPC code를 오류정정부호로 고려하고, 제한된 반복복호 횟수를 가지고 개선된 성능을 얻기 위해 새로운 복호 알고리즘을 제안하였다. 또한, 제안한 복호 알고리즘에 대해 모의실험을 통하여 성능을 검증함으로써 차세대 UWB 송수신 기술로서의 유용성과 적용 가능성을 제시하였다.

• Journal of Advanced Navigation Technology
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• v.13 no.6
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• pp.854-860
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• 2009

Ubiquitous is a new computing environment with IT technology and information communication, and appling various equipments likes PDA and application parts. Recently, user's using environment is changing to smart phone and is expanded learning tools to learner without educational environment. Thus, in this paper, we designed SCORM based meta-data to use smart phone. For this purpose, we made U-learning server and smart phone process server that is to handling with existence LMS and SCORM. To apply smart phones characteristics that have different ones each other, meta-data was able to have some resource information as like CPU, screen size and memory. The meta-data adapter could be process the characteristics.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.5
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• pp.103-108
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• 2005

In this article, it has been shown that penises devices such as illumination facilities, heating/cooling systems and security equipment can be controlled even outside premises using UPnP (Universal Plug and Play) applicable to the Internet or cellular phone services. To load UPnP protocol into each device, current manufacturers will be required to port flexible OS (Operating System), that is, Windows or Linux to these premises devices. Furthermore, prospective users want to experience a variety of specific functions based on more standardized and stable network. This study aims to provide application by implementing these functions on the Linux system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.386-389
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• 2006

At ubiquitous environment of the future, the platform that is mobile and suitable in such environment transmit and receive many data freely. In medical treatment field, medical device with advancement of the sensor and multimedia technique will develop as the household and hand-held device. So It will be developed as the health care device easily exchanging data to other devices and transmitting information of medical device to server. In this paper, currently the mobile platform based on the PXA255 such as a powerful microprocessor which connected the WLAN for guaranteeing a mobility and a speed transmits medical information to hospital server. It put an importance in providing the system for an efficient service.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1835-1839
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• 2008

Power management is a very important issue in portable electronic applications. Portable electronic devices require very efficient power management like LDO to increase the battery life. As the voltage variation of battery power is large in the application of cell phone, camera, laptop, automotive, industry application and so on, battery power is not directly used and LDO is used to supply the power of internal circuit. Besides, LDO can supply DC voltage that is lower than bauer voltage and constant DC voltage that is not related to largely fluctuated battery power. In the study, the power-save mode current and IR-drop characteristics are analyzed from a LDO with on-chip fabricated in 0.18-um CMOS technology.

• Journal of IKEEE
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• v.13 no.4
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• pp.116-124
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• 2009

Recently the CPU performance of modem chipsets or multimedia processors of mobile phone is as high as notebook PC. That is why mobile phone has been emerged as a leading ICON on the convergence of consumer electronics. The various applications of mobile phone such as DMB, digital camera, video telephony and internet full browsing are servicing to consumers. To meet all the demands the image quality has been increasingly important. Mobile phone is a portable device which is widely using in both the indoor and outside environments, so it is needed to be overcome to deteriorate image quality depending on environmental light source. Furthermore touch window is popular on the mobile display panel and it makes contrast loss because of low transmittance of ITO film. This paper presents the image enhancement algorithm to be embedded on image enhancement SoC. In contrast enhancement, we propose Clipped histogram stretching method to make it adaptive with the input images, while S-shape curve and gain/offset method for the static application And CIELCh color space is used to sunlight readability enhancement by controlling the lightness and chroma components which is depended on the sensing value of light sensor. Finally the performance of proposed algorithm is evaluated by using histogram, RGB pixel distribution, entropy and dynamic range of resultant images. We expect that the proposed algorithm is suitable for image enhancement of embedded SoC system which is applicable for the small-sized mobile display.

• Journal of Digital Convergence
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• v.13 no.5
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• pp.177-185
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• 2015

The gender difference in social roles affects digital devices' utilization differences in man and woman even in the 21st Century. Prior studies analyze the digital divide (genders, ages, etc.) from the assessment perspectives of digital equipment, such as PCs. In the area of high speed internet, most functions of PCs have been replaced with smartphones, and around 80% of the mobile phone users adopt smartphones. Subsequently the inequality of physical access to the digital devices is no longer a criterion for digital divide. The focus on digital divide should be shifted from the physical access to other factors, such as socio-technical or socio-cultural ones. This paper examines utilization of women's digital equipment, in particular, preparing for tourism activities, which is popular but sensitive to the technology. A survey was conducted with participants of [Suncheon Garden Expo] 2013. The results of this study capture the inactive use of digital devices particularly women over 50s. This phenomenon (high utilization of the digital devices for social or informative purposes, but low utilization of the digital payment) implies other aspects of Korean women (economic independence, low self-assertion, technical difficulties, etc.), which is considered from the socio-technological convergence perspective. This study also has a practical implication on the side of the digital device developers as well as marketing, where the qualitative communication is likely to be incorporated for the women over 50s.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.11
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• pp.48-55
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• 2016

Ambient-light sensor system, which changes the brightness of a display as ambient light change, was studied to reduce the power consumption of the mobile applications such as note PC, tablet PC and smart phone. The ambient-light sensor system should be integrated on a display panel to improve the complexity and cost of mobile applications, so the ambient-light sensor and readout circuit was integrated on a display panel using low-temperature poly-silicon thin film transistors (LTPS-TFT). We proposed the new compensation method to correct the panel-to-panel variation of the ambient-light sensors, without additional equipment. We designed and investigated the new readout circuit with the proposed compensation method and the analog-to-digital converter for the final digital output of ambient light. The readout circuit has very simple structure and control timing to be integrated with LTPS-TFT, and the input luminance ranges from 10 to 10,000 lux. The readout rate is 100 Hz, and maximum differential non-uniformity with 20 levels of the final output below 0.5 LSB.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1700-1706
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• 2014

In this paper, a step down converter for LED backlight of mobile application has been proposed. The converter which is operated with 4 MHz high switching frequency is capable of reducing mounting area of passive devices consists of a power stage and a control block. Circuit elements of the power stage are inductor, output capacitor, MOS transistors and feedback resistors. The control block consists of pulse width modulator, error amplifier and oscillator etc. Proposed step down converter has been designed and verified using a $0.35{\mu}m$ 1-poly 4-metal BCD process technology. Simulation results show that the output voltage is 1.8 V in 3.7 V input voltage, output current 100 mA which is larger than 25 ~ 50 mA in conventional 500 KHz driven converter when the duty ratio is 0.4.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.700-712
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• 2011

Due to recently advanced electrical devices, human can access computer network regardless of working location or time restriction. However, currently widely used mouse, joystick, and trackball input system are not easy to carry and they bound user hands exclusively within working space. Those make user inconvenient in Ubiquitous environments.. In this paper, we propose multiple dimension human motion detection system based on wireless sensor networks. It is a portable input device and provides easy installation process and unbinds user hands during input processing stages. Our implemented system is comprised of three components. One is input unit that senses user motions and transmits collected data to receiver. Second is receiver that conveys the received data to application, which runs on server computer. Third is application that performs command operations according to received data. Experiments shows that proposed system accurately detect the characteristics of user arm motions and fully support corresponding input requests.