• Title/Summary/Keyword: Polarization analysis

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Circular Polarization Diversity in Indoor Wireless Mobile Environments

  • Ha, Deock-Ho;Ko, Yeon-Hwa;An, Jae-Sung;Kim, Tai-Hong
    • Journal of electromagnetic engineering and science
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    • v.4 no.3
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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.

Proposal and Analysis of Wavelength-Switchable Optical Fiber Filter Based on a Solc Type

  • Kim, Min-Wook;Jung, Jae-Hoon
    • Journal of the Optical Society of Korea
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    • v.12 no.3
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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.

Polarization-Diversity Cross-Shaped Patch Antenna for Satellite-DMB Systems

  • Lim, Jong-Hyuk;Back, Gyu-Tae;Yun, Tae-Yeoul
    • ETRI Journal
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    • v.32 no.2
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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.

The Fabrication and Performance Estimation of Circularly Polarization Diversity System for Multipath Fading Reduction (다중경로페이딩 경감을 위한 원편파 다이버시티 시스템 제작 및 성능 평가)

  • 이주현;김판신;안재성;김태홍;고연화;김흥진;하덕호
    • Proceedings of the IEEK Conference
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    • 2003.07a
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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.

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Polarization Analysis of Ultra Low Frequency (ULF) Geomagnetic Data for Monitoring Earthquake-precusory Phenomenon in Korea (지진 전조현상 모니터링을 위한 ULF 대역 지자기장의 분극 분석)

  • Yang, Jun-Mo;Lee, Heui-Soon;Lee, Young-Gyun
    • Geophysics and Geophysical Exploration
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    • v.13 no.3
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    • pp.249-255
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    • 2010
  • Since the 1990's, a number of ULF geomagnetic disturbance associated with earthquake occurrences have actively been reported, and polarization analysis of geomagnetic fields becomes one of potential candidates to be capable of predicting short-term earthquake. This study develops the modified polarization analysis method based on the previous studies, and analyzes three-component geomagnetic fields obtained at Cheongyang geomagnetic observatory using the developed method. A daily polarization value (the ratio of spectral power of horizontal and vertical geomagnetic field) is calculated with a focus on the 0.01 Hz band, which is known to be the most sensitive to seismogenic ULF radiation. We analyze a total of 10 months of geomagnetic data obtained at Cheongyang observatory, and compare the polarization values with the Kp index and the earthquake occurred in the analysis period. The results show that there is little correlation between the temporal variations of polarization values and Kp index, but remarkable increases in polarization values are identified which are associated with two earthquakes. Comparison the polarization values obtained at Cheongyang and Kanoya observatory indicates that the increases of polarization values at Cheongyang might be due to not global geomagnetic induction but the locally occurred earthquakes. Furthermore, these features are clearly shown in normalized polarization values, which take account in the statistical characteristics of each geomagnetic field. On the basis of these results, polarization analysis can be used as promising tool for monitoring the earthquake-precursory phenomenon.

Effect of Chirp on Polarization Mode Dispersion and Polarization-Dependent Loss (PMD와 PDL에 미치는 chirp의 영향)

  • Yoon, Il-Yong;Lee, Yong-Wook;Lee, Byoung-Ho
    • Proceedings of the KIEE Conference
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    • 2002.07c
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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.

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A Computer-Aided Text Analysis to Explore Recruitment and Intellectual Polarization Strategies in ISIS Media

  • Khafaga, Ayman Farid
    • International Journal of Computer Science & Network Security
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    • v.22 no.8
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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.

The Effect of Selective Exposure of Political Orientation on Online Political Participation: Focusing on the Mediating Effect of Attitude Polarization (유튜브 정치성향에 따른 선택적 노출이 온라인 정치참여에 미치는 영향: 태도극화의 매개효과를 중심으로)

  • Lee, Min Kyu;Kim, Jung Hoon
    • The Journal of the Korea Contents Association
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    • v.22 no.4
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    • pp.261-272
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    • 2022
  • This study investigated the relationship between selective exposure, attitude polarization, and online political participation among 420 YouTube political video users. Additionally, the mediating effect of attitude polarization on the relationship between selective exposure and online political participation was examined. The main results were derived by conducting exploratory factor analysis, correlation analysis, and structural model analysis using the SPSS 21.0 program and AMOS 21.0 program. The results were presented as follows. First, selective exposure had a positive effect on attitude polarization. Second, selective exposure had a positive effect on online political participation. Third, attitude polarization had a positive effect on online political participation. Fourth, attitude polarization was found to mediate the relationship between selective exposure and online political participation. In summary, it was confirmed that selective exposure to YouTube political videos increased attitude polarization and online political participation, and the more the attitude polarization was strengthened by selective exposure, the more it led to online political participation.

CP-OFDM System using Circular Polarization (원편파를 이용한 CP-OFDM 시스템)

  • 김병옥;하덕호
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2001.11a
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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.

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Mobile Communication Group Polarization: Effects of Communication Cues and Anonymity

  • Suh, Eung-Kyo
    • Journal of Distribution Science
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    • v.14 no.8
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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.