• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.5
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• pp.141-162
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• 2017

The International Monetary Fund (IMF) crisis introduced a system for easy layoffs. With recent economic downturn, employees have been asked to retire early and less new jobs have become available. More small businesses as a result have been started. The purpose of this research is to study weight and ranking on SWOT factors of korea food service franchise industry using the SWOT analysis. The Analytic Hierarchy Process (AHP) and Analytic Network Process (ANP) were used to analyze the SWOT found by the surveys. First, the SWOT analysis shows that the franchise owners and the expert group view the industry positively overall and there are more strengths, opportunities than weaknesses, threats. While there are negatives and threats to the industry overall, many people think that there are more opportunities and positive aspects. Second, the franchise owners rank proven business model and platform (S3) as the strongest strength of food service franchise businesses while the expert group ranks management supports (S2) from headquarters as the strongest strength. Third, the expert group and franchise owner group indicate that the weight on unfair franchise contracts with headquarters(W3) and high penalty from breaking a franchise agreement(W4) are 60% of weaknesses. Fourth, both the expert group and franchise owner group indicate that change in people's lifestyle, value system and consumption pattern(O3) as the most important opportunity. Fifth, both groups indicate that changes in consumption pattern(T1) due to ever changing food service industry as the biggest threat. It is ranked higher than the entry of korea food service franchises.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.57-58
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• 2018

In this paper, we studied a design method for a quasi-Yagi antenna operating over a broad bandwidth covering the UHF RFID(902-928 MHz) and GNSS(1,164-1.605 MHz). The proposed antenna is composed of three elements(dipole, reflector, and director) and fed by a coplanar waveguide. To reduce its size, a balun is integrated inside the antenna, and the ends of both the dipole and reflector are bent. Broadband impedance matching was obtained by placing the director near to the dipole and loading a chip capacitor inside the antenna. The antenna, designed through simulations, was fabricated on an FR4 substrate with 0.8 mm thickness. The experiment results for the antenna characteristics agree very well with the simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.63-64
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• 2017

In this paper, we studied a design method for a coplanar waveguide-fed compact quasi-Yagi antenna for a dual band of the UHF RFID (915 MHz) and GPS (1.575 GHz). The proposed antenna is composed of three elements of a dipole, a reflector, and a director. To reduce its size, the ends of both the dipole and reflector are bent, the director is placed near to the dipole, and a balun is incorporated in the antenna. From some simulations, the proposed antenna using an FR4 substrate with 0.8 mm thickness was designed for the operations in the UHF RFID and GPS systems, and the antenna characteristics such as reflection coefficient, gain, and radiation patterns were examined.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.296-297
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• 2011

제5차 전력수급기본계획상 2014~2016년을 전후하여 경기북부지역 5.2GW, 충남서해안 6.9GW 등 발전설비의 특정지역 집중건설이 예정되어 있고, 해당 발전출력의 원활한 전송을 위해 계통보강이 이루어져야 한다. 발전설비 및 송전설비의 보강집중에 따라 계통 고장전류 증가가 불파기한 실정이다. 특히, 우리나라 부하의 약 40%가 집중되어 있고 지역의 넓이에 비해 송전망의 밀집도가 매우 높은 수도권의 경우, 고장전류가 해당 변전소의 차단기 정격차단용량을 초과하는 문제로 인해 계통을 분리하여 운전되고 있는 개소가 전국 계통분리개소의 50%를 넘는다. 본 고에서는 향후 국내 전력계통의 고장전류 증가추이를 전망하고, BTB-HVDC의 적용 등 고장전류저감방안에 대해 논 하고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.805-810
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• 2014

In this paper, the characteristics of a series-fed dipole pair antenna with an end-aligned strip pair director are studied. In the proposed SDP antenna, two strip dipole antennas with different lengths and a ground reflector are connected trough a coplanar stripline. The strip pair director placed above the second dipole element are two rectangular-shaped strips and is aligned at the ends of the two arms of the second dipole. The variations on the antenna performance for different lengths and widths of the director are analyzed, and optimal design parameters for the enhancement of the bandwidth are obtained. The optimized SDP antenna is fabricated on an FR4 substrate, and the experimental results show that the antenna has a frequency band of 1.65-2.95 GHz for a VSWR < 2, which shows enhanced bandwidth compared to the conventional SDP antenna.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.252-258
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• 2017

In this paper, the bandwidth and gain enhancement of a double-dipole quasi-Yagi antenna (DDQYA) using a modified balun and two directors is studied. The proposed DDQYA consists of two strip dipoles with different lengths, a ground reflector, which are connected through a coplanar strip line, and two directors. The modified balun is used to increase the bandwidth, whereas two directors are appended to the DDQYA to enhance the gain in the middle and high frequency band. The effects of the length and width of the first director on the antenna performance are analyzed, and final design parameters to obtain a gain over 7 dBi at 1.60-2.90 GHz band are obtained. A prototype of the proposed DDQYA is fabricated on an FR4 substrate, and the experimental results show that the antenna has a frequency band of 1.57-3.00 GHz for a VSWR < 2, and measured gain ranges 7.1-7.8 dBi at 1.60-2.90 GHz band.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.1
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• pp.1-7
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• 2017

In this paper, a design method for a compact stepped open slot antenna for an operation in the UWB band is studied. The proposed antenna is miniaturized by inserting L-shaped slots on the ground plane of the stepped open slot antenna through the creation of a resonance in the low frequency, and a strip director is appended to the antenna in order to increase the gain in the middle and high frequency regions. The effects of varying the length of the L-shaped slots, the distance between the director and the slot antenna, and the director length on input reflection coefficient and realized gain characteristics of the proposed antenna are analyzed. The optimized antenna with the size of $30mm{\times}30mm$ is fabricated on an FR4 substrate, and the experiment results show that the antenna has a frequency band of 3.02-11.04 GHz for a VSWR < 2, which assures the operation in the UWB band.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.70-73
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• 2012

In this paper, we introduce a design method for a quasi-Yagi antenna (QYA) with broadband characteristics of an impedance bandwidth ratio of > 2 : 1 and a gain of > 4 dBi. The QYA is fed by a microstrip line fabricated on a coplanar strip line and it consists of 3 elements; a planar dipole, a nearby director close to the dipole, and a ground plane reflector. By placing a rectangular patch-type director with large width near to the dipole driver, broadband characteristics are achieved. An optimized 3-element QYA for operation over 1.6-3.5 GHz (bandwidth ratio 2.2 : 1) is fabricated on an FR4 substrate with a size of $90mm{\times}90mm$ and tested experimentally. The results show an impedance bandwidth of 1.56-3.74 GHz (bandwidth ratio 2.4 : 1) for VSWR < 2, a peak gain of 4.41-6.53 dBi, and a front-to-back ratio (FBR) > 13.6 dB within the bandwidth.

• Journal of Advanced Navigation Technology
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• v.16 no.5
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• pp.760-765
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• 2012

In this paper, we studied a design method for a quasi-Yagi antenna (QYA) with broadband characteristics of an impedance bandwidth ratio greater than 2 : 1 and a gain > 4 dBi. The QYA is fed by a microstrip line fabricated on a coplanar strip line and it consists of 3 elements; a planar dipole, a nearby director close to the dipole, and a ground plane reflector. By placing a wide rectangular patch-type director near to the dipole driver, broadband characteristics are achieved. An optimized 3-element QYA for operation over 1.6-3.5 GHz (bandwidth ratio 2.2 : 1) is fabricated on an FR4 substrate with a size of 90 mm by 90 mm and tested experimentally. The results show an impedance bandwidth of 1.56-3.74 GHz (bandwidth ratio 2.4 : 1) for VSWR < 2, a peak gain of 4.2-6.3 dBi, and a front-to-back ratio (FBR) > 13.6 dB within the bandwidth.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.11
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• pp.1518-1523
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• 2018

A method for designing a DDQYA fed by a CPW is proposed in this paper. The proposed CPW-fed DDQYA consists of two series-connected strip dipoles, a ground reflector, and a strip-pair director. Instead of the conventional microstrip feed line in which the signal line is located on the substrate opposite to the antenna, a CPW is used because CPW is located on the same side with the antenna, and so the fabrication is easy. The strip-pair director is composed of two horizontally-separated strips, and it is added above the second dipole to enhance the gain in the high frequency region. A prototype of the proposed CPW-fed DDQYA is fabricated on an FR4 substrate. The fabricated antenna has a frequency band of 1.66-3.38 GHz(68.3%) for a voltage standing wave ratio < 2, and measured gain ranges 5.0-7.3 dBi over a frequency band of 1.60-2.90 GHz.