• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.4
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• pp.18-24
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• 2010

This paper presents the improvement of the field uniformity in a reverberation chamber which can be substitute an anechoic chamber for the electromagnetic interference (EMI) and immunity test. Nowadays, there are many EMI issues due to the increasing use of wireless local area network (LAN), digital multimedia broadcasting (DMB), and mobile internet. With this reason, this paper studied the field characteristics in a reverberation chamber for 2.3 GHz band. In this paper, the finite difference time domain (FDTD) method is used to analyze the field characteristics in a reverberation chamber. To improve the field uniformity in the reverberation chamber, this paper adopted a 2D cubical residue diffuser (CRD) with varying the disposition and number of CRD. For each case, the tolerance and standard deviation of the electric field strength are evaluated. In comparison with the reverberation chamber without any CRD, the reverberation chamber with two CRDs showed improved results; 1.98 dB improvement in standard deviation and 3.6 dB improvement in tolerance.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.1
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• pp.59-67
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• 2007

This paper presents a low power dual-level low voltage differential signaling (DLVDS) technique using current source switching for LCD driver ICs in portable products. The transmitter makes dual level signal that has two different level signal 400mVpp and 250mVpp while keeping the advantages of LVDS. The decoding circuit recovers the primary signal from DLVDS. The low power DLVDS is implemented using a $0.25{\mu}m$ CMOS process under 2.5V supply. The proposed circuit shows 800Mbps/2-line data rate and 9mW, 11.5mW power consumptions in transmitter and receiver, respectively. The proposed DLVDS scheme reduce power consumption dramatically compare with conventional one.

• Journal of Digital Contents Society
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• v.3 no.1
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• pp.59-74
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• 2002

Due to rapid advance of wireless communication technology and popularization of wireless devices, demand on wireless internet contents is gradually increasing. Therefore, there are many researches and solution developments to provide good qualified contents quickly for wireless internet. For example, researches into converting wired web contents into wireless web contents or using integrated markup language like XHTML basic to make contents. In this paper, I propose a method to develop XML-based web contents which uses PHP language for data fetch from MySQL database. This method use open source software for a cost saving. Due to use of PHP extension as a XSLT engine, this method is very easy to apply. For a example of this method, a web content of movie information is implemented for PC and PDA browser. Developing XML-based web contents is useful not only for supporting devices of multiple type, but also for rapid changes of user interface design and for exchange of contents between web sites.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.715-724
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• 2017

Today all kinds of smart devices are being developed with various researches on wearable devices that support smart computing on the human body. Skin diseases continue to rise including freckles, pimples, atopy, and scalp trouble due to the environmental and genetic factors, and people pay bigger medical bills to treat their skin diseases. There is thus a need to develop a smart-phone or table-based smart healthcare imaging system of high portability and diagnostic accuracy capable of analyzing and managing various skin problems related to skin care. This study proposed an integrated system combining the Smart Mi Band, a wearable device using moisture and UV sensors based on IoT, on the hardware part with the sensor information monitoring software.

• The KIPS Transactions:PartA
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• v.10A no.5
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• pp.479-486
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• 2003

As the Internet appliances like digital TV, Internet set-top boxes, and Internet phone, are showing up in the market, the economics of real-time operating system (RTOS), which is an essential for controlling those devices, is expanding faster than ever before. ETRI has developed describes RTOS called Qplus-P, targeting various platforms ranging from PDA to Internet set-top box and home server. This paper describes the implementation of graphic window library for Qplus-P. The Qplus-P graphic window library was implemented using tiny-X graphic server and gtk graphic toolkit, which are open source software. To port this library to various aliances, hangul processing, screen rotation, touch screen, and graphic acceleration functions are added to the tiny-X graphic server of the implementd graphic window library. Currently, Qplus-P graphic window is running on ARM-based appliances such as iPaq PDA, Samsung S3C2400 board, Zaurus PDA, and on Home Server that uses x86 processor. Qplus-P graphic library is provided as a of Qplus-P target builder.

• Information Systems Review
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• v.16 no.1
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• pp.17-35
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• 2014

Social collaboration and knowledge sharing among experts are the key characteristics of information system development projects. But the difficulty and complexity of communication may be the cause of the project failures. This study analyzes the influence of on-line social networking as communication system in information system development projects. A model has been developed to relate system, knowledge and social factors of on-line social networking to the performance of project members. Transactive Memory System (TMS), describing knowledge sharing process in human relationship, is used as a mediator. The analysis concludes that knowledge and social characteristics have positive effect on the members' performance, implying that the use of mobile devices and PCs as a social communication tool can be an effective way to enhance the possibility of project success.

• Journal of Korea Spatial Information System Society
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• v.11 no.3
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• pp.19-30
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• 2009

Recent development in wireless communication technology and mobile equipment like PDA, cellular phone and GPS makes location-based services (LBSs) popular. However, because, in the LBSs, users continuously request a query to LBS servers by using their exact locations, privacy information could be in danger. Therefore, a mechanism for users' privacy protection is required for the safe and comfortable use of LBSs by mobile users. For this, this paper propose a grid-based cloaking area creation scheme supporting continuous LBSs. The proposed scheme creates a cloaking area rapidly by using grid-based cell expansion to efficiently support the continuous LBSs. In addition, to generate a cloaking area which makes the exposure probability of a mobile user to a minimum, we compute a privacy protection degree by granting weights to mobile users. Finally, we show from a performance analysis that our cloaking scheme outperforms the existing cloaking schemes, in terms of service time, privacy protection degree.

• Journal of Digital Contents Society
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• v.14 no.3
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• pp.381-390
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• 2013

Almost all the mobile phone users already moved or are now moving away to smartphones for their various applications like games. If we are to speak about game applications, due to the performance limits of smartphones, 2D games are predominant over 3D games in every app. store. In this paper, we implement a 3D cube game application by porting an existing visual c++ irrlicht cube application to android platform library using the android Native Development Kit. After the porting is done, we add a few new features for more fun. Because the android NDK makes the existing C/C++ codes run directly on the android operating systems, we found by real execution tests that our 3D cube app. is well executed on a low-end android smartphone without any performance problem.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.465-468
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• 2007

An intelligent home network system using low-power and low-cost sensor nodes was designed and implemented. In Intelligent Home Network System, active home appliances control is composed of RSSI (Received Signal Strength Indicator) based user indoor location tracking, dynamic multi-hop routing, and learning integration remote-control. Through the remote-control learning, home appliances can be controlled in wireless network environment. User location information for intelligent service is calculated using RSSI based Triangle measurement method, and then the received location information is passed to Smoothing Algorithm to reduce error rate. In order to service Intelligent Home Network, moreover, the sensor node is designed to be held by user. The gathered user data is transmitted through dynamic multi-hop routing to server, and real-time user location & environment information are displayed on monitoring program.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.140-141
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• 2010

터치패널은 키보드나 마우스와 같은 입력장치를 사용하지 않고, 스크린에 손가락, 펜 등을 접촉하여 입력하는 방식이다. 누구나 쉽게 입력할 수 있는 장점으로 인해 기존에는 현금인출기, 키오스크 등 공공분야에 주로 많이 사용되어 왔으나, 최근의 터치스크린은 휴대폰, 게임기, 네비게이션, 노트북 모니터 등 개인정보기기의 입력장치로 활용분야가 넓어져가고 있다. 기존 터치패널은 유리 기판 위에 ITO박막(투명전도막)을 진공코팅하여 사용하여 왔지만, 최근 터치패널은 경량화를 고려하여 PET 필름 기판 위에 ITO 박막을 진공코팅하여 사용하고 있다. PET 필름의 유연성 때문에 ITO 코팅된 필름을 PC 혹은 강화유리 위에 OCA 물질을 이용하여 다시 고정하여야 한다. 이때 터치패널 제작시 생산공정이 늘어나 생산성이 떨어지고, 터치패녈의 광투과율도 떨어지는 2차적인 문제가 발생한다. 이를 해결코자하는 터치페널 업체의 needs가 있고, 최근에 이를 해결하기 위하여 PC, 강화유리, 그리고 COP 기판 위에 ITO 박막을 직접 진공코팅하는 공정개발이 진행되고 있다. ITO 박막은 진공코팅 중에 열을 가하여 결정화를 이루어야 하는데, PC, 강화유리 그리고 COP 기판의 열에 약한 특성을 고려하여, 열을 가하지 않고 ITO 박막을 진공코팅하여야 한다. 이러한 ITO 박막의 진공코팅 공정에는 In-line magnetron sputtering system이 사용된다. 본 연구에서는 In-line magnetron sputtering system을 사용하여 강화유리 기판 위에 터치패널용 고투과율 투명전도성 ITO 박막을 제작하고 그 특성을 조사하였다. ITO 박막의 면저항은 230Ohm/cm2, 최고 광투과율은 90.96%(@541~543nm), 그리고 550nm에서 광투과율은 90.45%로 ITO 박막 코팅 전후에 투과율 차이가 0.4임을 확인하였다. 정전용량방식의 터치패널에서는 ITO 박막 코팅 전후에 투과율 차이가 1 이하의 특성을 필요로 하는데, 이는 ITO 박막 패턴후에 패턴이 보이지 않게 하기 위해서이며, 이러한 시장의 needs를 고려하면 본 연구에서 매우 중요한 연구성과를 얻었다고 말할 수 있다.