• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.3
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• pp.437-444
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• 2000

In this paper, we propose a method that directly converts 3D CAD files for handheld phones designed by a commercial CAD S/W, PATRAN, to FDTD modeling with 1mm resolution. To qualify the accuracy of this method, we compared the calculation of radiation pattern using 3D transient far zone transformation with the measured results by gain comparison method in anechoic chamber and the difference is less than 0.5 dB. The calculation of magnetic field distributions on the front of handheld phones has been done to find a factor contributes to SAR. The result showed up the H-field in the width direction of the phone gives more dominant effect than the field in the length or inside to the front direction.

• Journal of Biomedical Engineering Research
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• v.32 no.4
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• pp.285-288
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• 2011

In this study, we developed an optical coherence tomography(OCT) using a sweep-source laser whose center wavelength is 1310 nm and a probe of hand-held type. The developed hand-held probe targets to diagnose the middle ear, so it is miniaturized for ease and convenience of control. For the first time, we performed in-vivo clinical experiments on tympanic membrane(TM) perforation patients not reported from previous studies about OCT. The high-resolution sectional images of tympanic membrane perforation can be obtained. There aren't many studies about diagnostic instrument of the middle ear and diagnosis with sectional image of the middle ear, so the developed OCT system and hand-held probe are applicable to tympanic membrane perforation and other pathologic diagnosis in the middle ear.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.836-858
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• 2010

Web Services allow a user to integrate applications from different platforms and languages. Since mobile applications often run on heterogeneous platforms and conditions, Web Service becomes a popular solution for integrating with server applications. However, because of its verbosity, XML based SOAP messaging gives the possible overhead to the less powerful mobile devices. Based on the mobile client's behavior that it usually exchanges messages with Web Service continuously in a session, we design the Handheld Flexible Representation architecture. Our proposed architecture consists of three main components: optimizing message representation by using a data format language (Simple_DFDL), streaming communication channel to reduce latency and the Context-store to store context information of a session as well as redundant parts of the messages. In this paper, we focus on the Context-store and describe the architecture with the Context-store for improving the performance of mobile Web Service messaging. We verify our approach by conducting various evaluations and investigate the performance and scalability of the proposed architecture. The empirical results show that we save 40% of transit time between a client and a service by reducing the message size. In contrast to solutions for a single problem such as the compression or binarization, our architecture addresses the problem at a system level. Thus, by using the Context-store, we expect reliable recovery from the fault condition and enhancing interoperability as well as improving the messaging performance.

• IE interfaces
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• v.22 no.4
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• pp.347-358
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• 2009

Panning tasks caused by both a small screen and the lower resolution of handheld devices are known to decrease the usability of a mobile internet service. To solve this problem, we proposed FTND, an improved version of Tap-N-Drag widely used in various mobile web browsers. 30 participants performed the panning tasks with FTND embedded in combinations of 2 panning directions of Push Background user interface and Push Viewpoint user interface and 5 panning ratios of 100% (a panning ratio of Tap- N-Drag), 300%, 500%, 700%, and 900%. The usability of FTND was assessed by an objective performance and a subjective preference. The objective performance was measured by a task completion time, the number of clicks, and the number of pixels. The subjective preference was measured by satisfaction, accuracy and ease of use. Push Viewpoint user interface at the panning ratios of 300%, 500%, and 700% proved to be the most efficient way for panning tasks with small handheld devices when performing the task by using the right hand thumb.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1314-1319
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• 2017

A handheld sheet resistance meter that can easily and quickly measure the sheet resistance of indium tin oxide films was developed. The dual-configuration four-point probe method was adopted for this instrument, which measured sheet resistance in the range from $0.26{\Omega}/sq$. to $2.6k{\Omega}/sq$. with 0.3 % ~ 0.5 % uncertainty. The screen of the instrument displayed the sheet resistance when the probe was in contact with the sample surface and the value continued to be displayed during the probe contact. Even after separating the probe from the surface, the value was still displayed on the screen and could be read easily. A feature of the instrument was the use of the dual-configuration technique to reduce edge effects markedly compared with the single-configuration technique and its ease of operation without applying correction factors for sample size and thickness.

• Journal of the Optical Society of Korea
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• v.15 no.1
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• pp.74-77
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• 2011

We report a novel extension of 840 nm wavelength- based spectral domain optical tomography to in vivo/real-time human middle ear diagnosis. The system was designed to access the middle ear region with a specifically dedicated handheld probe. The real-time displaying feature was mandatory for in vivo imaging human subject with the handheld probe, and the system could provide about 20 frames per second for 2048 pixels by 1000 A-scans without using any graphics process units under the Labview platform. The inner ear structure of a healthy male volunteer was imaged with the developed system with the axial and lateral resolutions of $15\;{\mu}m$ and $30\;{\mu}m$, respectively. The application of the OCT technology to early diagnose otitis media(OM) is very promising and could be another extensive branch in the OCT field because it provides the depth resolved image including tympanic membrane (TM) and structures below TM whereas the conventional otoscope technique only gives asurface image of the TM.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.705-711
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• 2022

Roadway lighting is an integral element of a highway system. Luminaires on roadways provide viewing conditions for drivers and pedestrians during nighttime in order to improve safety. It is time-consuming and labor-intensive to manually measure roadway illuminance at predetermined spots with a handheld illuminance meter. To improve the efficiency of illuminance measurement, a remote-control electrical cart and a drone were utilized to carry an illuminance meter for the measurements. The measurements were performed on the marked grid points along the pavement. To measure the illuminance manually, one person measures illuminance at each grid point with the handheld meter and another person records the illuminance value. To measure the illuminance with the remote-control cart, the illuminance meter is attached to the cart and it measures illuminance values continuously as the cart moves along the grid lines. With the drone, the meter records the illuminance continuously as the drone carries the meter and flies along the grid line. Because the drone can fly at different heights, the measurements can be done at different altitudes. The illuminance measurements using the cart and the drone are described in detail and compared with manual measurements in this paper. It is shown through this study that automated measurements can greatly improve the efficiency of roadway illuminance data measurements.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.862-866
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• 2002

This study was performed to analyze aroma pattern of Panax species (Korean Panax ginseng C.A. Meyer, Chinese Panax ginseng C.A. Meyer, Panax quinquefolium L, and Panax notoginseng F.H. Chen) by the PHGC (potable handheld gas chromatograph). Ratios of several peak areas in chromatogram of derivative parrtern were as follows. If ratio of Korean Panax ginseng was 1, Panax notoginseng was $0.030{\sim}0.674$, Chinese Panax ginseng was $0.005{\sim}0.212$ and panax quinquefolium was $0.241{\sim}0.871$. Ratios of peak area at $Rt_{20.02}$ were that if Korean panax ginseng was 1, Chinese Panax ginseng was 0.212, Panax quinquefolium was 0.343 and Panax notoginseng was 0.065. Ratios also of peak area at $Rt_{21.70}\;and\;Rt_{24.90}$ showed clear difference among aroma patterns of Panax specie cultivars. Flavor component at $Rt_{26.15}$ was not detected in Panax quinquefolium and Panax notoginseng but in Korean Panax ginseng and Chinese Panax ginseng. Ratios of peak area at $Rt_{26.15}$ were that if Korean Panax ginseng was 1, Chinese Panax ginseng was 0.185. And so habitat of Panax species cultivars was discriminated. Cultivar and habitat of dried panax species was remarkably distinguised by the chromatogram of frequency pattern, derivative pattern and visual pattern using olfactory images known as Vapor $print^{TM}$.

• Information and Communications Magazine
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• v.26 no.10
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• pp.18-24
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• 2009

본고에서는 북미 차세대 모바일 DTV(Digital Television) 규격인 ATSC-M/H(Mobile/Handheld) 기술의 주요 특징을 살펴본다. ATSC-M/H 기술은 6MHz 대역폭을 통해 총 19.39Mbps의 전송률을 지원할 수 있는 ATSC(Advanced Television Standard Committee) 시스템에서 HD 콘텐츠 전송 시 생성되는 여유 공간에 모바일 콘텐츠를 추가하여 전송하는 기술로 최대 120km/h의 이동속도를 지원한다. ATSC-M/H는 모바일 서비스를 위한 별도의 주파수 할당이 필요 없고, 기존 ATSC 시스템에 간섭을 주지 않으면서 동시방송이 가능하며, 저렴한 투자비용으로 모바일 방송 시스템을 구축할 수 있는 특징이 있다.

• Journal of information and communication convergence engineering
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• v.6 no.2
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• pp.169-171
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• 2008

An internal antenna for small mobile systems is proposed to support the DVB-H system. It consists of two antenna elements, which are a folded planar monopole for DVB-H and PIFA for GSM/DCS/PCS, and a meander line and RF cable are used to increase the ground plane. Experimental results of the antenna are presented.