• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1628-1634
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• 2011

With the advancement of ubiquitous computing technology, u-Healthcare (i.e. ubiquitous health care), is regarded as a key application for information society, which provides health management service at anytime in anywhere. To implement U-Healthcare system, it is essential to monitor stable biological information in daily life. In this paper, we proposed a small size, light weight, patch type real time temperature monitoring system based on wireless sensor network (WSN) technology to monitor patients' body temperature without any inconvenience of activity.

• Structural Engineering and Mechanics
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• v.50 no.4
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• pp.525-539
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• 2014

Bonded composite-patch repair has been widely used to restore or extend the service life of damaged structures due to its effectiveness as a mechanical repair technique. In this paper using extended finite element method (XFEM), three-dimensional crack models are developed to examine the fracture behavior of centrally cracked aluminum plates repaired with single and double sided composite patches. Stress intensity factor (SIF) at the crack tip is used as the fracture criterion. In this regard, the effects of the crack lengths, patch materials, orientation of plies, adhesive and patch thickness are examined to estimate the SIF of the repaired plate and the repair performance. The obtained results show that composite patches have significant effect on reduction of the SIF at the crack tip. It is also proved that using double symmetric repair, in comparison to single one, reduces considerably SIF at the crack tip. Hence, the residual strength can be improved significantly as well as fatigue life of the structure. Investigation of ply orientation effects shows SIF increase as the ply orientation is changed from $0^{\circ}$ (perpendicular to the advancing crack) to $90^{\circ}$ (parallel to the crack line). However, the effectiveness of the ply orientation depends on the loading direction and the crack direction.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.1
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• pp.7-11
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• 2004

In this paper, the wideband microstrip patch antennas for the Personal communications Service (PCS : 1750∼1870 MHz) and International Mobile Telecommunications-2000 (IMT-2000 : 1920∼2170 MHz) dual band are studied. Experimental and simulation results on the dual band antenna are presented. Simulation results are in good agreement with measurements. The experimental and simulation results confirm the wideband characteristics of the antenna. The studied antenna satisfied the wideband characteristics that are required characteristics for above 420 MHz impedance bandwidth for the PCS and IMT-2000 dual band antenna. In this paper, through the designing of a dual band antenna, we have presented the availability for PCS ＆ IMT-2000 base station antenna. An impedance bandwidth of 33% (VSWR<1.5, 650 GHz) and a maximum gain of 7dB can be achieved. The radiation pattern is stable across the passband.

• Journal of Advanced Navigation Technology
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• v.27 no.3
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• pp.281-286
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• 2023

This paper proposes a design of a wideband array antenna involving the downlink bands of fixed satellite service (FSS) and broadcasting satellite service (BSS) by applying two mixed patch sets. The proposed antenna is implemented on FR4 substrate by arranging rectangular patches in 6 by 2. To design a wideband antenna (10.7~12.75 GHz) covering both FSS downlink bands (10.7~10.95 GHz, 11.2~11.45 GHz) and BSS downlink bands (11.7~12.5 GHz, 12.2~12.75 GHz, 11.7~12.2 GHz), rectangular patches working at 11.5 GHz and 12.5 GHz are arranged alternately, and thus the proposed antenna can obtain a wide bandwidth equivalent to 30.8% of the center frequency. The proposed antenna was fabricated and measured, and the results are well matched with the simulated ones. From the performances, the proposed antenna can be applied to the receiving antenna for FSS and BSS downlinks.

• Journal of electromagnetic engineering and science
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• v.18 no.4
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• pp.261-266
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• 2018

This paper reports on the proposed design of a low profile broadband array antenna for home repeater applications. The proposed antenna consists of $1{\times}4$ patch elements and two ground planes, one of which is slitted. By using the gap feeding method, the impedance matching of the antenna is improved by a multi-resonance phenomenon. The proposed antenna provides a wide -10 dB reflection coefficient bandwidth simultaneously covering the Global System for Mobile communications (GSM-1800), Personal Communications Service (PCS), and the Universal Mobile Telecommunication System (UMTS) bands (1.67-2.32 GHz). In order to reduce the mutual coupling between adjacent patch elements, slits are embedded in the ground plane. An isolation level of -20 dB is realized over the entire operating frequency band.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.11a
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• pp.230-233
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• 2003

In this paper, the wideband microstrip patch antennas for the Personal communications Service $(PCS\;:\;1750\~1870\;MHz)$ and International Mobile Telecommunications-2000 $(IMT-2000\;:\;1920\~2170\;MHz)$ dual band are studied. Experimental and simulation results on the dual band antenna are presented. Simulation results are in good agreement with measurements. The experimental and simulation results confirm the wideband characteristics of the antenna. The studied antenna satisfied the wideband characteristics that are required characteristics for above 420 MHz impedance bandwidth for the PCS and IMT-2000 dual band antenna. In this paper, through the designing of a dual band antenna, we have presented the availability for PCS & IMT-2000 base station antenna. An impedance bandwidth of $31\%(VSWR<1.5,\;615\;MHz)$ and a maximum gain of 7dBi can be achieved. The radiation pattern is stable across the passband.

• Korean Journal of Digital Imaging in Medicine
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• v.11 no.2
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• pp.79-84
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• 2009

Recently, there has been a rapid increase of interest in u-Health systems or instruments. The importance of testbeds has been discussed deeply also. However, beyond laboratory or ward environments, testbeds covering metropolitan area cannot be found easily. Moreover, there has been few papers which discuss the results of testbed operations for various instruments in different age groups. In this paper, the results of testbed which operated in Daegu metropolitan area are discussed and improvement directions to strengthen the competitiveness are proposed using user analysis. In particular, the results of trial services using the u-Life support instruments (medication reminder, falling safety phone, bio-patch and shirts, etc) for super aging societies in the near future are discussed.

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.2
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• pp.45-58
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• 2005

The propose of this study investigated the reproduction of color image displayed on a CRT monitor, for a range of different values of monitor gamma. We have used the GOG(gain-offset-gamma) model of the behavior of the CRT. Color difference have been computed in a color space, based on the CIELAB color appearance model. The 133 patch defined linearly color sample and 24 patch defined printing color target were used, and were subjected to the influence of nine different gamma value. The result show that neutral color is increasing the decrease range of luminance black color than white color. These results are of concern in the context of the "correct" display of color reproduction.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.3
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• pp.465-470
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• 2007

This paper is designed and producted the microstrip patch antenna which used aperture coupled feed structure, and had a comparatively hish gain and headband characteristic with a PCS substitution repeater antenna. The proposed antenna transformed a coupled slot into a H-type in order to improve a characteristic of a general aperture coupled feed antenna. It is this H-type form slot reduces back lobe from the antenna backside at the same time that a coupling between a power feed and patches is iccreased, and to have maximized a gain of an antenna. As a result of having measured the antenna which the VSWR was 1.5 or below and tied up the gain than 7.5dBi in the $1750{\sim}1870$[MHz] that was a PCS substitution, and a beamwidth became in $80^{\circ}$ and radio waves shadow was local, but accomplishment did PCS mobile communication service in building me smoothly, but confirmed what practical use can become.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.375-380
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• 2005

In this paper, We studied an antenna for the wireless home network service. From the structural modification of patch and ground plane, we made a reverse heart shape radiated pattern of antenna which is suited to wireless home network service. As a result, bandwidth between maximum gains is 110 degree, and the difference of downward direction gain from maximum gain have become -3.6dB. Installing the antenna on the ceiling, horizontal plane of the inner home will be formed the uniform electromagnetic environment. Accordingly, stable reception level acquisition and outdoor radiated suppression could be possible.