• 제목/요약/키워드: Reception Function

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Simplified RBF Multiuser Receivers of Synchronous DS-CDMA Systems (Synchronous DS-CDMA 시스템에서의 간략화된 RBF 다중사용자 수신기)

  • 고균병;이충용;강창언;홍대식
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.5C
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    • pp.555-560
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    • 2003
  • For synchronous direct sequence-code division multiple access (DS-CDMA) systems, the authors propose an adaptive radial basis function (RBF) receiver with suboptimal structure that reduces not only the complexity with regard to the number of centers but also the quantity of instructions required per one bit reception. The proposed receiver is constructed with parallel RBF networks. Each RBF network has the same procedure as the conventional RBF receiver. The performance of each RBF network is affected by interferences which are assigned to the other RBF networks because neither RBF network uses the full user set. To combat these interferences, the partial IC technique is employed. Monte Carlo simulations over additive white Gaussian noise (AWGN) channels confirm that the proposed receiver with its reduced complexity is able to obtain near-optimum performance. Moreover, the proposed receiver is able to properly cope with a various environment.

PAPR Reduction Technique and BER Performance Improvement in OFDM-based Wireless Visible Light Communication (OFDM을 사용하는 무선 가시 광통신에서의 PAPR 저감 기법과 BER성능 개선)

  • Ryu, Sang-Burm;Ryu, Heung-Gyoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.3A
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    • pp.189-197
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    • 2011
  • OFDM systems are much studied for the recent high speed wireless optical communication system. OFDM system has basically high PAPR and ICI easily generated because of non-linearity and RF impairments. In the wireless optical communication system, optical output power driven by current of LED is not linear so that transmission signals are distorted. Therefore, research about reception performance of this nonlinear optical output emitted by non-linear LED transfer function and OFDM signal has been conducted. Nonlinear effect of LED is different from nonlinear effect of OFDM system in the conventional radio communication system, which degrades the BER performance. In this paper, we apply non-linear transfer function of recently studied LED into OFDM system. So, for reducing the PAPR and suppressing the ICI in frequency domain of receiver, we suggest a new PAPR reduction technique to reduce non-linear distortion of LED and an adaptive ICI suppression algorithm so that BER performance may be improved. Also, the proposed method is verified through simulation results.

Microbial Rhodopsins: Genome-mining, Diversity, and Structure/Function

  • Jung, Kwang-Hwan;Vishwa Trivedi;Yang, Chii-Shen;Oleg A. Sineschekov;Elena N. Spudich;John L. Spudich
    • Journal of Photoscience
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    • v.9 no.3
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    • pp.45-48
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    • 2002
  • Microbial rhodopsins, photoactive 7-transmembrane helix proteins that use retinal as their chromophore, were observed initially in the Archaea and appeared to be restricted to extreme halophilic environments. Our understanding of the abundance and diversity of this family has been radically transformed by findings over the past three years. Genome sequencing of cultivated microbes as well as environmental genomics have unexpectedly revealed archaeal rhodopsin homologs in the other two domains of life as well, namely Bacteria and Eucarya. Organisms containing these homologs inhabit such diverse environments as salt flats, soil, freshwater, and surface and deep ocean waters, and they comprise a broad phylogenetic range of microbial life, including haloarchaea, proteobacteria, cyanobacteria, fungi, and algae. Analysis of the new microbial rhodopsins and their expression and structural and functional characterization reveal that they fulfill both ion transport and sensory functions in various organisms, and use a variety of signaling mechanisms. We have obtained the first crystallographic structure for a photosensory member of this family, the phototaxis receptor sensory rhodopsin II (SRII, also known as phoborhodopsin) that mediates blue-light avoidance by the haloarchaeon Natronobacterium pharaonis. The structure obtained from x-ray diffraction of 3D crystals prepared in a cubic lipid phase reveals key features responsible for its spectral tuning and its sensory function. The mechanism of SRII signaling fits a unified model for transport and signaling in this widespread family of phototransducers.

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Performance of Radio Communication DS/CDMA System with Diversity Technique and BCH Coding under Impulsive Noise and Nakagami Fading (임펄스 잡음과 나카가미 페이딩이 존재할 때 다이버시티 기법과 오류정정 부호를 이용한 무선통신 DS/CDMA 시스템의 오율 특성)

  • 김지웅;강희조;이권현
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.10 no.4
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    • pp.539-549
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    • 1999
  • In this paper, the bit error rare (BER) performance of DS/CDMA DQPSK communication system in the presence of multi access interference, impulsive noise and Nakagami fading is investigated. The DS/CDMA DQPSK communication system adopts Maximum Ratio Combining (MRC) diversity reception and error correcting BCH code technique to enhance system performance. Using the derived error probability equation, the error rate performance of DS/CDMA DQPSK communication system has been evaluated and shown in figures to discuss as a function of impulsive index(A), Gaussian noise to impulsive noise power ratio($\Gamma$'), multi access interference(Κ), Nakagami fading parameter(m), the number of diversity branch (L), the number of error correction symbol (t), PN code sequence length(N) and $E_b/N_0$. The error performance of DS/CDMA-MDPSK signals improve by adopting MRC diversity and BCH(15,7) coding technique in the environment of impulsive noise plus Nagakami fading. From the results, we known that proposed system is affected by multi access interference, impulsive noise and Nakagami fading in radio communication system environment. Also, BER performance of DS/CDMA DQPSK communication system cam be improved increasing either the power of desired signal or the value of Gaussian noise to impulsive noise power ratio. And BCH(15,7) code technique is more effective to restrain the affection of multi access, interference, impulsive noise and Nakagami fading in DS/CDMA DQPSK communication system than MRC diversity reception technique.

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The Effects of Medical Service Quality of the Nursing Hospital in Japan on the Inpatients' Satisfaction and Reuse Intention (일본 요양병원 의료서비스 품질이 입원환자 만족도와 재이용의도에 미치는 영향)

  • Hwang, Sun-Ja
    • The Journal of the Korea Contents Association
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    • v.18 no.11
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    • pp.581-593
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    • 2018
  • The purpose of this study is to examine the effect of the medical service quality of the nursing hospital on the inpatients' satisfaction, reuse intention and to verify the mediating effect of the inpatients' satisfaction. The subjects of this study were 255 male and female inpatients in Hiroshima in Japan. The collected data were used as a model of path coefficients obtained through analysis of covariance structure and hypothesis test. As a result of verification, level of medical team and medical service, reception, facility and fee of the medical service quality of the nursing hospital perceived by the inpatients showed a statistically significant positive correlation with the inpatients' satisfaction. The inpatients' satisfaction showed a statistically significant positive correlation with their reuse intention. The level of medical team and medical service, reception, facility and fee of the medical service quality of the nursing hospital perceived by the inpatients shows a statistically no significant positive correlation with the reuse intention. But, they show a statistically significant positive correlation with the reuse intention with the mediating effect of the inpatients' satisfaction. Finally, the result of this study is to confirm the effect of the medical service quality on the inpatients' satisfaction, reuse intention of the nursing hospital. In this process, it is meaningful to verify the role and function of medical service quality of the nursing hospital.

The Power Relevant to Curatorship (큐레이터십과 관련된 권력)

  • Lee, Ji-Ho
    • The Journal of Art Theory & Practice
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    • no.3
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    • pp.51-66
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    • 2005
  • With the advent of the time when the competitiveness of a nation or a city can be evaluated by the extent of cultural reception, the art exhibitions, like other genres of art, are actively held in various ways by different institutions. The spaces of exhibition offered not only by public museums and galleries but also by private galleries, alternative spaces and open-air exhibition spots are being increased. Likewise, the number of exhibitions organized on a large scale by Biennales and local governments is on the increase. In accordance with actual tendency, the Ministry of Culture and Tourism has planned to increase the number of museums and galleries up to 500 by the year of 2011. Under these circumstances, the actual situation shows that the central and local governments are adopting beneficial measures to support the private galleries such as permission of construction on green belt areas and tax deduction. That is, our society has come to realize that the necessity and importance of public as well as private galleries to play their roles as cultural and educational institution. Now, the number of galleries is growing. Exhibitions are held everywhere. Therefore, spectators have more chance to visit them than before. With these conditions and the growing number of amateurs, social interest in curator organizing exhibitions is getting popular. Because of the rise of curatorial popularity on the social level, the influence of curators which is exercised within the gallery seems to become gradually enlarged. In reality, it is true that the curatorial influence cannot be ignored more than ever for appear in various fields their new features made from their professional cometence. The function of gallery is more strengthened and its position is more heightened than those in 80s. For these reasons, the curators whose playground is the gallery, they may be regarded as invisible power to the artists. Futhermore, their influence as such seems to be more likely because our world of art does not still have any reliable system of art criticism. Nevertheless, considering the actual situation in which national and public galleries as cultural institution would rather exist on the local sentiments or political dynamics than on autonomy, there must be some restrictions for the galleries and the curators to obtain the power. In this context, the actual moment is looked upon as transitional period to make the curatorship settled down. Before discussing the power relevant to curatorship, we are going to examine first the role and function of curator and then the new curatorial role and function at the age of information. Finally, we will see in sequence the development and problems of curatorship, the power and dilemmas of curator.

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Improvement of Performance in the DS-CDMA / DPSK Cellular Mobile Communication System using CCI Canceller and MRC Diversity (DS-CDMA/DPSK 셀룰라 이동통신 시스템에서 간섭 제거기와 최대비 합성 다이버시티에 의한 성능의 개선)

  • 우병훈;오창헌;조성준
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.5 no.1
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    • pp.22-30
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    • 1994
  • The error probability of the DS-CDMA / DPSK cellular mobile communication system with CCI canceller and MRC diversity reception technique has been analyzed in the cellular radio channel which is characterized by AWGN, Multi-User Interference(MUI) and m-distribution fading. System capacity i. e., number of user per cell has been derived and the evaluated results are shown in figures as a function of PN code sequence length, fading index, BER, number of diversity branches and $E_b/N_o$, Here, the voice activity factor is assumed to be 3/8, the number of sectors in a cell 3 and Multi-User Iner- ference is modeled as Gaussian process.

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Media Platform Design for Terrestrial Ultra-High Definition(UHD) Broadcasting Service (UHD 방송서비스를 위한 지상파 방송의 플랫폼 구축 연구)

  • Oh, Jai-Pil;Kim, Min-Ki;Kim, Seong-Kweon;Kim, Dong Ho
    • Journal of Satellite, Information and Communications
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    • v.9 no.1
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    • pp.6-12
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    • 2014
  • The traditional broadcasting service has advanced into a smart media service with the help of communication network. in In the smart media ecosystem, a variety of innovative media services have been provided by new players. However, terrestrial broadcasting service companies seem to lag comparatively behind new players in spite of their powerful contents production capacity and stable terrestrial media delivery networks. In this paper, we design a proposed media platform based on a set-to-box (STB) with various new function for terrestrial ultra-high definition(UHD) broadcasting service. Also we suggest specific transmission network architecture and platform components for UHD broadcasting service. The proposed media platform is expected to increase the number of direct home reception and to enhance the right of the free-viewers which is one of the natural mission of terrestrial broadcasting company. Also it can provide some profit model of UHD terrestrial broadcasting service with new value-added services.

Unconscious Signs in Visual Signification of Lacan's Metaphor (라캉 은유의 시각적 의미작용을 통한 무의식적 기호 연구)

  • Park, Sang-Hyeok
    • The Journal of the Korea Contents Association
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    • v.15 no.4
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    • pp.88-96
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    • 2015
  • The universe of discourse presented in the visual image is bound up with the experience and culture of parties; its sender and recipient. Signification of visual message is revealed through the mutual independent process. The mechanism where production of signifiant by sender and reception of metaphoric signifiant function unconsciously can be applied to Lacan's theory;"The unconscious is structured like a language". By applying Lacan's metaphoric formula which takes linguistic approach to visual image it is suggested that analysis of signification is possible. This analysis can be a base for seeking varied level of signifiant presented in visual metaphor logically and practically. Metaphoric structure of the signifiant and the matrix analysis can develop a creative idea and propose a practical way for the visual image production. Thus empirical study about nastic response and the future analysis result is expected to be possible.

Application of Digital On-Channel Repeater in a DTV Transmission Network in Korea (국내 DTV 방송망에서의 디지털 동일채널중계기의 적용)

  • Suh Young-Woo;Kim Young-Min;Mok Ha-Kyun;Kwon Tae-Hoon;Lee Sang-Gil;Park Sung Ik;Lee Yong-Tae;Eum Homin;Seo Jae Hyun;Kim Heung Mook;Kim Seung Won
    • Journal of Broadcast Engineering
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    • v.10 no.4 s.29
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    • pp.587-598
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    • 2005
  • KBS and ETRI have co-developed an advanced DOCR(Digital On Channel Repeater) which has an equalization and pre-distortion function and can be operated properly under lower isolation of reception and transmission antennas. Field tests of the DOCR were performed twice in Suwon area in 2004 and 2005. This paper summarizes the characteristics of the DOCR system and field test results in Suwon. The changes in DOCR coverage according to the different generations of ATSC DTV receivers were also analyzed. Basic concept to apply the DOCR system in DTV broadcasting networks in Korea is suggested through test results.