• Title/Summary/Keyword: Common space

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Space Vector PWM Method for Leakage Current Reduction and NP Current Control in 3-phase 3-level Converter used in Bipolar DC Distribution System (양극성 DC 배전용 3상 3-레벨 컨버터의 누설전류 저감과 NP 전류 제어를 위한 공간벡터 PWM 방법)

  • Lee, Eun-Chul;Choi, Nam-Sup;Kim, Hee-Jun
    • The Transactions of the Korean Institute of Power Electronics
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    • v.23 no.5
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    • pp.336-344
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    • 2018
  • This study proposes a new PWM method for leakage current reduction and neutral point (NP) current control in three-phase three-level converter employed in bipolar DC distribution systems. The proposed PWM method uses medium vectors only when there is no need to control the NP current. Thus, common mode voltages are held constant to realize zero leakage current. Some space vectors that produce low-frequency common mode voltages are employed to minimize leakage currents when the average NP current needs to be a positive or negative value. The proposed space vector PWM is implemented based on barycentric coordinate. The validity of the proposed PWM method is verified by simulations and experiments.

A Bayesian State-space Production Assessment Model for Common Squid Todarodes pacificus Stock Caught by Multiple Fisheries in Korean Waters (한국 해역의 살오징어(Todarodes pacificus) 개체군 자원평가를 위한 베이지안 상태공간 잉여생산량 모델의 적용)

  • An, Dongyoung;Kim, Kyuhan;Kang, Heejung;Hyun, Saang-Yoon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.5
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    • pp.769-781
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    • 2021
  • Given data about the annual fishery yield of the common squid Todarodes pacificus, and the catch-per-unit-effort (CPUE) data from multiple fisheries from 2000-2018, we applied a Bayesian state - space assessment model for the squid population. One of our objectives was to do a stock assessment, simultaneously incorporating CPUE data from the following three fisheries, (i) large trawl, (ii) jigger, and (iii) large purse seine, which comprised on average a year about 65% of all fisheries, allowing possible correlations to be reflected. Other objectives were to consider both observation and process errors and to apply objective priors of parameters. The estimated annual exploitable biomass was in the range of 3.50×105 to 1.22×106 MT, the estimated intrinsic growth rate was 1.02, and the estimated carrying capacity was 1,151,259 MT. Comparison with available results from stock assessment of independently analyzed single fisheries revealed a large difference from the estimated values, suggesting that stock assessment based on multiple fisheries should be performed.

Relationship between Le Corbusier's Errazuris House Project and Antonin Raymond's Karuizawa Villa (르 코르뷔지에의 에라즈리스 주택계획안과 안토닌 레이몬드의 카루이자와 별장의 상관성에 관한 연구)

  • Kim, Kyoung-Yon;Jun, Byung-Kweon
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.1
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    • pp.15-22
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    • 2018
  • Raymond, who adopted Le Corbusier's Errazuris House Project, built Karuizawa Villa by incorporating Japan's aspiration for Western modern architecture and strong convictions regarding the preservation of traditional culture heritage, which were prevalent in Japan at the time. Despite the controversy over his plagiarism, Karuizawa Villa shows several unique architectural characteristics. First, in terms of the arrangement and access system, the villa has a common space that affords a view of the lake by accessing from the mountain side. Second, in terms of spatial composition, the common space is connected to the mesonnette by placing a trail to enable enjoyment of natural scenery. In particular, personal space is planned in the shape of a cross by connecting several surfaces to the outside in order to secure enjoyment of the natural environment. Lastly, in the aspect of structure and materials, both architectural buildings adopted masonry by using natural stone as well as building materials suitable for each region and climate by using logs in constructing the main columns and beams. Through Karuizawa Villa, Raymond is considered to have established his own style by combining the standard of Western modern architecture and the elements of Japanese traditional architecture while valuing local architectural technology.

STRONG CONVERGENCE THEOREMS FOR ASYMPTOTICALLY QUASI-NONEXPANSIVE MAPPINGS AND INVERSE-STRONGLY MONOTONE MAPPINGS

  • He, Xin-Feng;Xu, Yong-Chun;He, Zhen
    • East Asian mathematical journal
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    • v.27 no.1
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    • pp.1-9
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    • 2011
  • In this paper, we consider an iterative scheme for finding a common element of the set of fixed points of a asymptotically quasi nonexpansive mapping and the set of solutions of the variational inequality for an inverse strongly monotone mapping in a Hilbert space. Then we show that the sequence converges strongly to a common element of two sets. Using this result, we consider the problem of finding a common fixed point of a asymptotically quasi-nonexpansive mapping and strictly pseudocontractive mapping and the problem of finding a common element of the set of fixed points of a asymptotically quasi-nonexpansive mapping and the set of zeros of an inverse-strongly monotone mapping.

COMMON FIXED POINT RESULTS FOR GENERALIZED ORTHOGONAL F-SUZUKI CONTRACTION FOR FAMILY OF MULTIVALUED MAPPINGS IN ORTHOGONAL b-METRIC SPACES

  • Leyew, Bahru Tsegaye;Mewomo, Oluwatosin Temitope
    • Communications of the Korean Mathematical Society
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    • v.37 no.4
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    • pp.1147-1170
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    • 2022
  • In this paper, we introduce a new class of mappings called the generalized orthogonal F-Suzuki contraction for a family of multivalued mappings in the setup of orthogonal b-metric spaces. We established the existence of some common fixed point results without using any commutativity condition for this new class of mappings in orthogonal b-metric spaces. Moreover, we illustrate and support these common fixed point results with example. The results obtained in this work generalize and extend some recent and classical related results in the existing literature.

A Study on Design Elements of Main Control Room in Nuclear Power Plants by Analyzing Space Characteristics (원자력발전소 주제어실의 공간특성에 따른 디자인 요소에 관한 연구)

  • Lee, Seung-Hoon;Lee, Tae-Yeon
    • Korean Institute of Interior Design Journal
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    • v.19 no.6
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    • pp.249-256
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    • 2010
  • For guaranteeing for security of nuclear power plant, ergonomic factors have been applied to design of main control room, core area for management and control of nuclear power plant, but design elements for performance of operators have been ignored. As the behaviors of operators are important for security of nuclear power plant, space design which makes them pleasant psychologically and makes them maintain attention on security equipments ceaselessly is required. Therefore, the purpose of this study is to analyze space characteristics of main control rooms according to regulations of nuclear power plant and general guidelines of space design, and to offer basic data for designing of main control room which makes operators pleasant psychologically and physically. At first, theoretical issues related with design of main control room are reviewed and several premises of space are developed by abstracting design elements from common space and regulations of nuclear power plant and, then integrating each design elements interactively. In short, the improvement of system environment based on human-machine interface space has brought about perceptual, cognitive, and spatial changes and has realized next generation of main control rooms. And, differences and similarities between ordinary space and main control room, which ergonomic sizes and regulations are applied and is VDT environment based on LDP, are discussed in relation to 13 design elements and 17 space premise.

A new active common mode voltage Damper to suppress high frequency leakage current of PWM Inverter (새로운 능동형 커먼 모드 전압 감쇄기를 이용한 PWM 인버터의 고주파 누설전류 억제)

  • 구정회;이상훈;박성준;김철우
    • The Transactions of the Korean Institute of Power Electronics
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    • v.6 no.5
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    • pp.423-431
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    • 2001
  • This paper proposes a new active common-mode voltage damper circuit that is capable of suppressing a common-mode voltage produced in the PWM VSI-fed induction motor drives. The new active common mode voltage damper is consists of a four-level half-bridge Inverter and a common mode transformer with a blocking capacitor. In order to reduce the common mode voltage and high frequency leakage current the active common mode damper applies to the PWM inverter system the compensated voltage of which the amplitude is the same as the common mode voltage and of which the polarity is opposite to the common mode voltage. Simulated using P-SPICE and experimental results show that common-mode voltage damper makes contributions to reducing a high frequency leakage current and common-mode voltage.

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