• Journal of electromagnetic engineering and science
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• v.8 no.1
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• pp.28-33
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• 2008

We have proposed a novel DVB-H(Digital Video Broadcast for Handheld) antenna for folder-type mobile handheld terminal by using a coupling element, a stub, and an L-type matching circuit. The L-type matching circuit consisting of two chip inductors is used for achieving an improved impedance matching over the DVB-H frequency band ($470{\sim}702\;MHz$). Simulated results showed the stub worked to more knot the lower and upper frequency ends of the input impedance curve. The antenna exhibits a flat gain characteristic from 2 to 2.8 dBi over the DVB-H frequency band. The radiation patterns are a stable Figure-of-eight radiation pattern in the frequency range.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.4
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• pp.39-45
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• 2009

With the rapid growth of recent wireless mobile computing application technology and handheld mobile terminal device development technology, one of the big issue in these fields is to design online games in wireless mobile ad hoc network environment. Online games in mobile computing environment have lots of constraints for developing online games because mobile terminals have many limitations such as low performance of processor, limited memory space, small bandwidth of wireless communication, and confined life of battery power. Therefore, most of mobile games are restrictive in the function of online and multi-play up to date. In this paper, the online MMORPG game, capable of multi-play with many other mobile users using mobile terminals in wireless mobile computing environment, is designed and implemented. Proposed mobile online game uses bluetooth to construct temporary wireless mobile ad hoc network with other mobile clients, and designed to carry out online MMORPG game with these clients. It also supports multi-play among them.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.5
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• pp.135-142
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• 2013

With a rapid growth of hardware and product material industries, evolution of handheld terminal technologies is progressed. Various applications using mobile phone are the major trend in recent smart applications. Especially, interesting applications using camera module in a smartphone are developed continuously, mobile users are able to use various useful mobile applications nowadays. In this paper, we design and implement smartphone app for measuring real size of the shooting object in the image taken by a camera module in a smartphone precisely. We implement 4 different shooting modes for precise measurement of objects and 0 point control module is developed to minimize the differences of shooting images taken by different types and systems of various smartphones. The smartphone app proposed and implemented in this paper is analyzed and evaluated by a simulation study.