• Title/Summary/Keyword: PWA

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RHC for Nonlinear backlash system control (RHC를 이용한 비선형 Backlash 시스템 제어)

  • Yoo, Kyung-Sang
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.2471-2473
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    • 2005
  • We present a receding horizon control [RHC] algorithm for compensation of backlash at the input of a stable linear system under control rate constraints. The problem is posed as a receding horizon optimal control [RHOptC] problem for a piecewise affine [PWA] system by modelling the backlash nonlinearity as a PWA system with a state space partition consisting of three regions. The RHC problem involves solving, at each step, $3^N$ quadratic programmes[QP], where N is the optimization horizon. This strategy leads, at the cost of some performance degradation, to much smaller computational load since a feasible rather than optimal solution has to be obtained at each step.

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Microstructure and Corrosion Characteristics of Al-Si Diffusion Coated Ni Base Super alloy (Al-Si확산코팅에 따른 Ni기 초합금의 미세조직과 부식특성)

  • 안종천;김택수;윤동주;이경구
    • Journal of the Korean institute of surface engineering
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    • v.32 no.2
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    • pp.100-108
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    • 1999
  • The microstructure and corrosion properties of Al-Si diffusion coated PWA1426 alloy have been investigated. Experimental variables are included temperatures of heat-treatment and coating thickness. The microstructure of coated layer and corrosion properties were analysed by SEM, EDS and hot corrosion test. Two major processes have been found to contribute to microstructural changes in the coating. These are, firstly, the transformation of the NiAl to other $Ni_2Al_3$-based phase and secondly, the precipitation of Cr containing phases. Specimens heat treated at $1080^{\circ}C$ showed superior corrosion resistance to heat treated at $880^{\circ}C$. These increase in life was attributed to the transformation of NiAl and increased coating thickness of PWA1426 alloy.

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Piecewise Affine Control Design for Power Factor Correction Rectifiers

  • Tahami, Farzad;Poshtkouhi, Shahab;Ahmadian, Hamed Molla
    • Journal of Power Electronics
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    • v.11 no.3
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    • pp.327-334
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    • 2011
  • Single-phase power factor correction (PFC) converter circuits are non-linear systems due to the contribution of their multiplier. This non-linearity causes difficulties in analysis and design. Models that reduce the system to a linear system involve considerable approximation, and produce results that are susceptible to instability problems. In this paper a piecewise affine (PWA) system is introduced for describing the nonlinear averaged model. Then robust output feedback controllers are established in terms of the linear matrix inequality (LMI). Simulation and experiments results show the effectiveness of the proposed control method.

ELISA of rat sera infected with Paragonimus iloktsuenensis (이락촌폐흡충 감염 쥐의 혈청에 대한 효소면역 반응(ELISA))

  • Im, Byeong-Gil;Lee, Ok-Ran;Nam, Hae-Seon
    • Parasites, Hosts and Diseases
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    • v.28 no.4
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    • pp.207-212
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    • 1990
  • Enzyme-linked immunosorbent assay(ELISA) of paragonimiasis iloktsuenensis rat sera was performed using crude antigens of Paragonimus iloktsuenensis(PIA), P. westermani (PWA) and Clonorchis sinensis(CSA). Three crude antigens(PIA, PWA, CSA) were prepared to saline homogenated supernatants of whole adult worms. Infected rat sera were obtained biweekly from the albino rats fed 50∼.80 metacercariae of P. iloktsuenensis through gastric catheter. Experimental groups were divided into 4 groups: GI(controls), GII, GIII and GIV according to 1∼7 worms as GII, 10∼19 worms as GIII and 22∼40 worms as GIV, respectively, In ELISA, the mean OD values of each group for the homologous antigen(PIA) were increased significantly compared to the control sera at the 4th week of infection. With the progress of duration of infection, the mean OD values of infected sera of GII & GIV continuously increased up to the 12th week(last week), but in GIII the mean OD value increased until the loth week. No significance was noted among the infection dose groups (GII, GIII and GIV), after the 6th week of infection. Also, the OD values of all infected rats did not show any Proportional relytionships to the number of worms recovered. In brief, the antibody productivity of individual rats were strongly different. The rat sera infected with p. iloktsuenensis cross-reacted with those infected with P. westermani or C. sinensis, as identified by OD values.

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Characterization of Concrete Composites with Mixed Plastic Waste Aggregates (복합 폐플라스틱 골재 치환 콘크리트의 기초 물성 평가)

  • Lee, Jun;Kim, Kyung-Min;Cho, Young-Keun;Kim, Ho-Kyu;Kim, Young-Uk
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.3
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    • pp.317-324
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    • 2020
  • Plastic wastes generated from domestic waste are separated by mixed discharge with foreign substances, and the cost of the separation and screening process increases, so recycling is relatively low. In this study, as a fundamental study for recycling mixed plastic wastes generated from domestic waste into concrete aggregates, changes in concrete properties according to the plastic waste types and the substitution rate were evaluated experimentally. The mixed plastic waste aggregate(MPWA) was found to have a lower density and a higher absorption rate compared to the coarse aggregate with good particle size distribution. On the other hand, the single plastic waste aggregate(SPWA) was composed of particles of uniform size, and both the density and the absorption rate were lower than that of the fin e aggregate. It was found that the MPWA substitution concrete did not cause a material separation phenomenon due to a relatively good particle size distribution even with the largest amount of plastic waste substitution, and the amount of air flow increased little. The compressive strength and flexural strength of the PWA substitution concrete decreased as the amount of substitution of the PWA increased due to the low strength of the PWA, the suppression of the cement hydration reaction due to hydrophobicity, and the low adhesion between the PWA and the cement paste. It was found that the degree of deterioration in compressive strength and flexural strength of concrete substituted with MPWA having good particle size distribution was relatively small.

Serodiagnosis of human paragonimiasis by ELISA-inhibition test using monoclonal antibodies (단클론항체를 이용한 폐흡충증의 면역진단)

  • Yong, Tae-Sun;Seo, Jang-Hun;Yeo, In-Seok
    • Parasites, Hosts and Diseases
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    • v.31 no.2
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    • pp.141-148
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    • 1993
  • ELISA-inhibition test using Paragonimus westermani specific monoclonal antibody (Mab) was investigated to improve the diagnostic specificity of paragonimiasis. By cell fusion, one hybridoma clone secreting un-n westemanl specific Mab was selected (Pwa-14), which reacted on bands of 28 kDa, 42.5 kDa, 89 kDa and 120.5 kDa. IFA showed Pwa-14 was located at the vitelline follicles. By micro-ELISA, 100% of 22 paragonimiasis cases were found positive, but 5 of 40 clonorchlasls cases (12.5%),3 of 26 cystlcercosis cases (7.7%) showed false positive. None of 10 sparganosis patients or 28 normal controls reacted positively. On the other hand, by ELISA-Inhibition test using a R westermcni specific Mab, 100% of patagonimlasls cases were found positive, and there were no positive in cysticercosis, sparganosis cases or normal controls, except 2 (5.0%) false-positive sera of 40 clonorchiasis cases. The ELISA-Inhlbltlon test using a Mab showed higher specificity in comparison with macro-ELISA for serodlgnosis of human paragonimlasis.

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Preparation and application of gel type polymer electrolyte for PEFC (PEFC 연료전지용 겔 타입 고분자 전해질 합성 및 응용)

  • Lee, Sang-Yong;You, Ji-Yeon;Kim, Han-Joo;Oh, Mee-Hye;Park, Soo-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.42-45
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    • 2003
  • Inorganic polymer based hybrid membranes consisting of zirconium oxide and polydimethylsiloxane (PDMS) have been synthesized by sol-gel processes. The hybrid membranes showed thermal stability and flexibility up to $300^{\circ}C$. The membrane becomes proton conducting polymer electrolyte when added with 12-phosphotungstic acid (PWA). The conductivity of the membranes was measured in the temperature range from room temperature to $150^{\circ}C$ under saturated humidity and a maximum conductivity of $5{\times}10^{-5}\;Sm^{-1}$ was obtained at $150^{\circ}C$.

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Novel Detection Algorithm of The Upstroke of Pulse Waveform for Continuously Varying Contact Pressure Method (연속 가압방식의 맥파 측정방법을 위한 시작점 검출 알고리즘 개발)

  • Bae, Jang-Han;Jeon, Young-Ju;Kim, Jong-Yeol;Kim, Jae-Uk
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.49 no.2
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    • pp.46-54
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    • 2012
  • We propose a continuously varying contact pressure(CVCP)-adaptive feature extraction algorithm for pulse diagnostic analysis. The CVCP method measures the pulse waveform with continuously increasing contact pressure(CP). This method offer a high resolution signal of the pulse waveform amplitude(PWA) as a function of the contact pressure. Therefore it enables us to overcome the limitation of commercially available pulse-taking devices whose analysis rely on a few number of PWA-CP pairs. We show that an efficient feature extraction algorithm which covers the features of the CVCP-method can be developed by sequentially applying Fast Fourier Transform, peak detection by center-to-edges method, baseline drift removal, detection of the percussion wave upstroke by intersecting tangent method and detection of the analysis region. Finally, by a clinical study with 30 subjects, we show that our CVCP-adaptive feature extraction algorithm detected the upstroke with accuracy of 99.46% and sensitivity of 99.51%, which were about 4.82% and 2.46% increases respectively, compared to a conventional feature extraction method. The proposed CVCP method and the CVCP-adaptive feature extraction algorithm are expected to improve the accuracy in the pulse diagnostic algorithms such as floating/sunken pulse qualities and deficient/excess pulse qualities.

The Development of Travel Data Sharing System using the Optical Character Reader. (광학문자 인식을 이용한 여행 정보 공유 시스템의 개발)

  • Park, Ju-Hyeon;Lee, Hyun-Dong;Kim, Dong-Hyun;Cho, Dae-soo
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2018.07a
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    • pp.189-190
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    • 2018
  • 최근에는 여행에 대한 각종 정보가 많이 공유되는 추세이다. 최근 사람들은 소셜 네트워크 서비스를 이용 중이거나 웹 서핑을 하는 도중에 기억하고 싶어 하는 여행지를 단순히 캡처 해놓거나 메모장에 기록해둔다. 이러한 방법은 시간이 지나 많은 데이터가 쌓이면 관리하기 어렵다는 문제가 존재한다. 본 논문에서는 사용자의 편리를 고려하여 사진의 텍스트를 광학식 문자 판독을 활용하여 출력하고 게시 글 형태로 저장할 수 있게 개발하였다. 명소의 위치 또한 자동완성 위치 검색 라이브러리를 통하여 편리 저장이 가능하다. 위치 데이터를 통해 향후 사용자가 근접하고 있는 여행지 또한 제공해줄 수 있도록 구현하였다. 이를 위하여 웹을 통해서 이용할 수도 있으며 실시간 검색과 알림 이벤트를 위해 웹 주소 입력 없이도 앱을 실행할 수 있는 프로그래시브웹 앱을 구현하였다.

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