• Journal of electromagnetic engineering and science
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• 제4권3호
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• pp.128-136
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• 2004

In this paper,. with the aim of achieving the expected performance improvement for a polarization diversity system, we analyzed two-branch polarization diversity at the receiving end of a mobile link which a transmitter emits circularly polarized wave. In this analysis, to calculate the correlation coefficient considered by XPD(cross polarization discrimination) between the two received signals, a simple theoretical model of circular polarization diversity is adopted. From the analysis results, it is clearly seen that the correlation coefficient of circular polarization diversity evaluated by the XPD is less than that of conventional linear polarization diversity. And also, we designed and implemented a circular polarization diversity system with micro-strip antenna. By using the circular polarization diversity system, we analyzed the measured data in indoor NLOS(Non-Line-Of-Sight) environments. From this analysis results, it is also clearly seen that the diversity effect of circular polarization diversity system shows better performance compared to the conventional linear diversity system by about 3 dB high.

• Journal of the Optical Society of Korea
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• 제12권3호
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• pp.147-151
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• 2008

This paper proposes a new polarization-independent Sagnac birefringence loop structure-based multiwavelength-periodic filter and presents measurements and analysis of its spectrum. The filter can be used in several schemes by adjusting the orientation angles of two quarter waveplates and the operating characteristics in the reflection type are analyzed including dispersion and polarization mode dispersion at each principal axis. This filter has polarization-independent spectra but a polarization-dependent dispersion, consequently polarization mode dispersion whose values changes with operating schemes.

• ETRI Journal
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• 제32권2호
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• pp.312-318
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• 2010

A small reconfigurable patch antenna is proposed to achieve polarization diversity for digital multimedia broadcasting systems at 2.6 GHz. To obtain polarization diversity, a pair of on-slit PIN diodes is inserted in each diagonal of a cross-shaped patch. Thus, four PIN-diodes on these slits are utilized to change the connection of the slits and thus achieve polarization. Bias circuits for the diodes are allocated in the cutting corner of the cross-shaped patch to minimize the antenna size. The antenna produces left-hand circular polarization, right-hand circular polarization, or linear polarization, depending on the PIN-diode status. Analysis of circular polarization operation is explicated. Measurements show a gain of about 1.5 dB, a cross polarization of about -20 dB, and an axial ratio of about 2.5 dB.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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• pp.609-612
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• 2003

For combating multipath fading in wireless radio environment, diversity schemes is useful. In this paper, for performance improvement of polarization diversity system, we analyzed a two-branch polarization diversity at the receiving end of a mobile link when the transmitter emits a circularly polarized wave. And In order to calculate the correlation coefficient considering the XPD(cross polarization discrimination) between the received signals for the two diversity branches, a simple theoretical model of circular polarization diversity is adopted and calculate correlation coefficient. From the analysis results, it is seen that the correlation coefficient of circular polarization diversity evaluated by the XPD is less than that of vertical polarization diversity. And also, we designed and fabricated circular polarization diversity system with microstrip antenna. we analyzed data measured in indoor NLOS environment using fabricated circular polarization diversity system. From the measurement results, it is clearly seen that the diversity effect of circular polarization diversity system is higher 3dB than vertical polarization diversity system.

• 지구물리와물리탐사
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• 제13권3호
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• pp.249-255
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• 2010

1990년대 이후 지진발생과 관련된 ULF 대역 지사가장의 변동이 다수 보고된 후, 분석 분석 방법을 이용한 지자기장 분석은 단기 지진예측에 큰 기여를 할 것이라 기대되고 있다. 본 연구는 기존 연구를 참조하여 개량된 분극 분석 방법을 개발하고, 이를 이용하여 청양관측소의 지자기 삼성분 자료를 분석하였다. 분석 주파수는 지진발생에 가장 민감하다고 알려진 0.01 Hz 대역이며, 수직 자기장과 수평 자기장의 분광에너지 비, 즉 분극값을 일단위로 계산하였다. 총 10개 월 동안의 사료가 분석되었으며, 분석경과를 Kp 인덱스 및 동일기간 발생한 지진이벤트와 비교하였나 청양의 분극값 변동은 Kp 인덱스와 관련성이 적었으며, 두 기간에서 지진발생과 관련한 주목할 만한 분극값의 증가가 관찰되었다. 일본 Kanoya 관측소의 자료와 비교해 본 결과, 청양의 분극값 증가는 광역적인 자기장의 변동에서는 지진발생과 밀접한 관계가 있는 것으로 생각된다. 또한, 자기장의 통계적 특성을 고려한 정규화된 분극값의 변동에서는 이러한 특징이 보다 뚜렷하게 확인된다. 따라서 분극 분석 방법은 지진전조형상 모니터링을 위해 유용하게 활용됨 수 있으며, 향후 추가적인 자료 확보 및 분석을 통해 지진발생과 관련된 ULF 변동을 탐지하는데 큰 기여를 할 수 있을 것으로 기대된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1939-1940
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• 2002

Numerical simulation for effect of chirp on PMD and PDL was accomplished. we assumed two uniform fiber concatenation with both polarization mode dispersion and polarization-dependent loss. We showed that polarization mode dispersion is increased with chirp parameter and polarization-dependent loss is decreased with chirp. And we accomplished mathematical analysis.

• International Journal of Computer Science & Network Security
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• 제22권8호
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• pp.87-96
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• 2022

This paper employs a computer-aided text analysis (CATA) and a Critical Discourse Analysis (CDA) to explore the strategies of recruitment and intellectual polarization in ISIS (Islamic State in Iraq and Syria) media. The paper's main objective is to shed light on the efficacy of employing computer software in the linguistic analysis of texts, and the extent to which CATA software contribute to deciphering hidden meanings of texts as well as to arrive at concise and authentic results from these texts. More specifically, this paper attempts to demonstrate the contribution of CATA software represented in the two variables of Frequency Distribution Analysis (FDA) and Content Analysis (CA) in decoding the strategies of recruitment and intellectual polarization in one of ISIS 's digital publication: Rumiyah (a digital magazine published by ISIS). The analytical focus is on three strategies of recruitment and intellectual polarization: (i) lexicalization, (ii) intertextual religionisation, and (iii) justification. Two main findings are revealed in this study. First, the application of CATA software into the linguistic investigation of texts contributes effectively to the understanding of the thematic and ideological messages pertaining to the analyzed text. Second, the computational analysis guarantees concise, credible, authentic and ample results than is the case if the analysis is conducted without the work of computer software. The paper, therefore, recommends the integration of CATA software into the linguistic analysis of the various types of texts.

• 한국콘텐츠학회논문지
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• 제22권4호
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• pp.261-272
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• 2022

본 연구는 유튜브 정치동영상 이용자 420명을 대상으로 정치성향의 선택적 노출과 태도극화 및 온라인 정치참여의 관계를 규명하였으며, 선택적 노출과 온라인 정치참여 관계에서 태도극화의 매개효과에 대해 살펴보았다. 자료는 SPSS 21.0 프로그램과 AMOS 21.0 프로그램을 이용하여 탐색적 요인분석과 상관관계분석, 구조모형분석을 실시하여 주요 결과를 도출하였다. 그 결과 첫째, 선택적 노출은 태도극화에 정적 영향을 미치는 것으로 나타났다. 둘째, 선택적 노출은 온라인 정치참여에 정적 영향을 미치는 것으로 나타났다. 셋째, 태도극화는 온라인 정치참여에 정적 영향을 미치는 것으로 나타났다. 넷째, 태도극화는 선택적 노출과 온라인 정치참여의 관계를 매개하는 것으로 나타났다. 요약하면, 유튜브 정치동영상에 대한 선택적 노출은 태도극화와 온라인 정치참여를 높이고 선택적 노출에 의해 태도극화가 강화될수록 온라인 정치참여로 이어진다는 사실을 확인하였다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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• pp.34-38
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• 2001

This paper proposes a CP-OFDM(Orthogonal Frequency Division Multiplexing using Circular Polarization) system for improving the system performance. The circular polarization has a characteristic that it cannot receive the reflected waves which are reflected by odd times. By reducing the influences of the reflected waves, the circular polarization can reduce the time delay spread and the inter-channel interference. The guard interval needed for the OFDM frame can be minimized and the orthogonality between subchannels can be improved by using circular polarization. Therefore the proposed CP-OFDM system can improve the system performance as well as the spectrum efficiency. Both theoretical analysis and system simulation results are described.

• 유통과학연구
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• 제14권8호
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• pp.101-112
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• 2016

Purpose - The objective of this study is to identify the effects of the communication cues and anonymity on group polarization in mobile communication settings, both in terms of route and extent. Research design, data and methodology - Laboratory experiments were conducted to achieve the above research objective; the effect of communication cues on group polarization with social presence as mediation and the direct effect of anonymity, social presence, and perceived cohesion were analyzed. The experiments were conducted by the participation of 240 people, who were divided into 48 groups of 5 people. Results - According to the results, the difference in intergroup polarization due to communication cues and anonymity was insignificant. From this analysis, the structural equation model, communication cues and anonymity did not affect group polarization through social presence. Moreover, anonymity did not affect group polarization through perceived cohesion; however, anonymity directly affected group polarization. Conclusions - This research can help to explain the discussions and the related decision-making actions on internet forums, which have recently come to the rise as well as provide foundational basis in newly establishing policies for the forums.