• Title/Summary/Keyword: Information space

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A Method to Compensate the Distorted Space Vectors in the Unbalanced Neutral Point Voltage of 3-level NPC PWM Inverters

  • Hyun, Seung-Wook;Hong, Seok-Jin;Lee, Jung-Hyo;Lee, Chun-Bok;Won, Chung-Yuen
    • Journal of Power Electronics
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    • v.16 no.2
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    • pp.455-463
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    • 2016
  • This paper proposes a compensation method to improve the distorted space vectors when a 3-level Neutral Point Clamped (NPC) inverter has an unbalanced neutral point voltage. Since both the neutral point voltage of the DC link and the space vector of a 3-level NPC inverter are closely related depending on the output load connecting state, a distorted space vector can occur when the neutral point voltage of a 3-level NPC inverter is unbalanced. The proposed method can improve the distorted space vectors by adjusting the injection time of the small and medium vectors and by modulating the amplitude of the carrier waveforms. In this paper, the proposed method is verified by both simulation and experimental results based on a 3-level NPC inverter.

A Study on the Creative Interface Factors of Library Space on Ito Toyo - Focus on the Tama Art University New Libraries - (이토토요의 도서관 공간에 나타나는 창조적 인터페이스요소에 관한 연구 - 타마미술대학신도서관을 사례로 -)

  • Hwang, Mee-Young
    • Korean Institute of Interior Design Journal
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    • v.19 no.3
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    • pp.205-213
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    • 2010
  • The importance of communication which is oriented to interaction, fusion and connection is more increased in the post-information society. The information environment is already realized as interface to reach immediately and freely to the databased information and knowledge. The contemporary libraries execute very important roles as an intellectual infra of modern times to deliver the great human achievement and create new culture. In the mean time, the rapid information-oriented society and the development of digital technology bring out big change in the traditional dispatch and receipt method of information. For this reason, libraries as the community space of visitors integrates physical space - electronic space and reconstructs new temporary culture and value to build the new interface that connects human to human, human to space and human to information. On the premise of these awareness, this study analysis the creative interface factor of Tama Art University New Libraries in Ito Toyo in order to research the function and the application method of modern libraries. And the results are follows. 1)We can make sure the significance of communication and the integration consciousness between digital technology and analogue sensitivity that is the characteristic of the post-information society. 2)We can classify for the creative interface factors by the character as space factor(Arcade, Gallery, Lounge, AV Booth, Cafe), facility/equipment factor(Laboratory, Media, Bar, Info Shelf, Media Seat) and furniture factor(Carrel, Desk, Mag Table, XI Shelf). 3)We can see that these interface factors change the stream of library users and that the library is constructed for library users to create and discovery something easily from books and modern technologies. And we can realize also that these factors are creative installation to lead out naturally the latent liberty sense of users.

A Study on the Space Program and Analysis of Optimal Land of National Scientific and Technical Information Center (국가과학기술문헌센터 공간구성 및 최적입지 현황분석 연구)

  • Hong, Hyun-Jin;Ko, Hyung-Gon;Kang, Mi-Hee;Jeong, Dae-Keun
    • Journal of Information Management
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    • v.34 no.4
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    • pp.1-17
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    • 2003
  • This research aims to find an optimal space program and analysis of optimal land of the national model of the scientific and technical information center. And the objective of this study is to contribute to strengthen the need of the building of information center and provide operation programs and vision toward information center which will be established later. We suggested a basic plan of scale and space program for proper space uses and optimal facilities and state-ofthe-art equipment of building. Also, we selected alternative land by document study, and suggested optimal land by field works and studies.

Study on the Spatial Standard for Data Reading Rooms in Public Libraries (공공도서관 자료열람실 공간기준에 관한 연구)

  • Lim, Ho-Kyun
    • Korean Institute of Interior Design Journal
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    • v.22 no.5
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    • pp.328-335
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    • 2013
  • This study investigated the ratios of area, according to the domains and functions, of a public library. To this end, 20 public libraries were selected as samples from the 2012 Public Library Construction Casebook and from cases of consulting on the construction and operation of public libraries. The domains of a public library were categorized into data reading, cultural education, operation, common use, and others. There was a large difference in the area ratios between public libraries that were built with the aid of consulting (Group B) and those without consulting (Group A). In functional terms, the data(bookshelf) space and reading space had similar ratios within a data reading room, while the ratio of the library information space was smaller. Within a general data reading room, the ratio of the library information space was 12%, while the ratios of the data space and seating space were 44%, respectively. Moreover, within a data reading room for children, the ratios of the library information space and children's space were adjusted to 14%, respectively, while the data space and seating space each accounted for 36%, with either 3- or 5-decker bookshelves installed. This study has identified how to calculate the area for each domain, capacity of books, and seating capacity by applying area ratios through functions in the data storage domain, along with numbers of books and seats per unit space. This study has also succeeded in calculating the required area and seats for each type of data storage room by applying the number of books that exist. However, this study has its limitation in that the regional characteristics(Metropolis, Small & medium size cities, Rural areas) were not considered because the number of samples was only 20 libraries.

Acquisition of Evidential Information to Control Total Volume in accordance with Degradation Trends of Green Space (녹피율 훼손추세 평가를 통한 총량규제 근거자료 학보방안)

  • Um, Jung-Sup
    • Spatial Information Research
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    • v.14 no.3 s.38
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    • pp.299-319
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    • 2006
  • This research is primarily intended to investigate the potential of estimating green space threshold in terms of total volume control using degradation trends of green space derived from remote sensing and GIS. An empirical study for a case study site was conducted to demonstrate how a standard remote sensing and GIS technology can be used to assist in estimating the total control volume for green space in terms of area-wide information, spatial resolution and change detection etc. Guidelines for a replicable methodology are presented to provide a strong theoretical basis for the standardization of factors involved in the estimation of the green space threshold; the meaningful definition of land mosaic, redefinition of degradation trends for green space. It was demonstrated that the degradation trends of green space could be used effectively as an indicator to restrict further development of the sites since the visual maps generated from remote sensing and GIS can present area-wide visual evidences by permanent record. It is anticipated that this research output could be used as a valuable reference to support more scientific and objective decision-making in introducing aggregate control of green space.

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Design of a Replicated Javaspace using Group Communication System (그룹통신 시스템을 이용한 복제 JavaSpace의 설계)

  • 문남두;이근웅;구형서;박양수;이명준
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04a
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    • pp.502-504
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    • 2002
  • JavaSpace는 쉽고 단일화된 방식으로 분산 어플리케이션간의 객체공유, 중재 및 동적인 통신서비스를 제공한다. 현재 Javaspace글 이용한 응용 프로그램들이 계속적으로 등장하고 있다. 기존의 JavaSpace는 중앙 집중적인 클라이언트/서버 방식으로 구현되었기 때문에 성능이 제한적이다. 본 논문에서는 그룹 참여자들간의 상태를 일관성 있게 유지시켜주는 그룹통신 시스템을 이용하여 분할가능한 분산환경에 적합한 복제된 Javaspace 시스템을 설계하였다. 복제된 JavaSpace 시스템을 이용하는 웅용 프로그램들은 효율성과 확장성을 증대시킬 수 있다.

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MULTIPLIERS OF WEIGHTED BLOCH SPACES AND BESOV SPACES

  • Yang, Gye Tak;Choi, Ki Seong
    • Journal of the Chungcheong Mathematical Society
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    • v.22 no.4
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    • pp.727-737
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    • 2009
  • Let M(X) be the space of all pointwise multipliers of Banach space X. We will show that, for each $\alpha>1$, $M(\mathfrak{B}_\alpha)=M(\mathfrak{B}_{\alpha,0})=H^\infty{(B)}$. We will also show that, for each $0<{\alpha}<1$, $M(\mathfrak{B}_\alpha)$ and $M(\mathfrak{B}_{\alpha,0})$ are Banach algebras. It is established that certain inclusion relationships exist between the weighted Bloch spaces and holomorphic Besov spaces.

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Serially Concatenated Space-Time LDPC Codes for High Data Rate Wireless Communication (고속 무선 통신을 위한 직렬 연접 시공간 LDPC 부호에 관한 연구)

  • 장혜경;이문호
    • Proceedings of the IEEK Conference
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    • 2002.06a
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    • pp.335-338
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    • 2002
  • For high data rate transmission over wireless fading channels, space-time trellis ceding techniques can be employed to increase the Information capacity of the communication system dramatically. In this paper, we consider the concatenated space time LDPC (Low Density Parity Check) codes. Extra ceding gains In addition to the diversity advantage is shown to be achieved for certain space-time trellis codes transmitted over quasi-static lading channels.

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On the Relationship Between the Performance Criteria of Unitary Space-Time Codes with Noncoherent and Coherent Decoding

  • Cheun, Kyung-Whoon;Kim, Jeong-Chang;Choi, Soong-Yoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.12A
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    • pp.1145-1151
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    • 2010
  • Hochwald et al. introduced unitary space-time codes for quasi-static Rayleigh fading channels which allows for noncoherent decoding when the channel response is not known at the receiver. However, when reliable information on the channel response is available, coherent decoding is preferable for improved performance. Here, we study the relationship between the performance criteria on the diversity and coding advantages provided by unitary space-time codes with noncoherent and coherent decoding. We show that when a unitary space-time code achieves full spatial diversity with noncoherent decoding, full spatial diversity is also guaranteed with coherent decoding.

Space-Polarization Division Multiple Access System with Limited Feedback

  • Joung, Heejin;Jo, Han-Shin;Mun, Cheol;Yook, Jong-Gwan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.4
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    • pp.1292-1306
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    • 2014
  • This paper proposes a space-polarization division multiple access (SPDMA) system that has limited feedback channels. The system simultaneously serves data streams to multiple mobile users through dual-polarized antenna arrays, by using pre-determined sets of precoding vectors that are orthogonal in both space and polarization domains. To this end, a codebook whose elements are sets of the precoding vectors is systematically designed based on the discrete Fourier transform (DFT) matrix and considering the power imbalance of polarized channels. Throughput of the SPDMA system is evaluated and compared to that of space division multiple access (SDMA) system, according to the various parameters including cross polarization discrimination (XPD). The results show that the throughput of SPDMA system outperforms that of SDMA in the environments of high XPD with many mobile users.