• 제목/요약/키워드: PE condition

검색결과 173건 처리시간 0.026초

불확실한 로봇 시스템을 위한 적응 반복 학습 제어 및 식별 (An Adaptive Iterative Learning Control and Identification for Uncertain Robotic Systems)

  • 최준영
    • 제어로봇시스템학회논문지
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    • 제10권5호
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    • pp.395-401
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    • 2004
  • We present an AILC(Adaptive Iterative Learning Control) scheme and a sufficient condition for system parameter identification for uncertain robotic systems that perform the same tasks repetitively. It is guaranteed that the joint velocity and position asymptotically converge to the reference joint velocity and position, respectively. In addition, it is proved that a sufficient condition for parameter identification is the PE(Persistent Excitation) condition on the regressor matrix evaluated at the reference trajectory during the operation period. Since the regressor matrix on the reference trajectory can be easily computed prior to the real robot operation, the proposed algorithm provides a useful method to verify whether the parameter error converges to zero or not.

The Correlation between Power Error and Velocity Error according to the Condition and Frequency of Self-Controlled Feedback during Knee Extension

  • Yoon, Jung Gyu
    • 국제물리치료학회지
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    • 제9권4호
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    • pp.1602-1607
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    • 2018
  • This study examined the correlation between power error (PE) and velocity error (VE) according to the condition and frequency of self-controlled feedback (SCF) during knee extension. One hundred participants were randomly assigned to 30% SCF, 70% SCF, 30% yoked feedback (YF), 70% YF and control group, respectively. The SCF group was provided with feedback when they requested it, whereas the YF group did not influence the feedback schedule. Participants in the control group were not given any visual feedback during the experiment. The isotonic, isometric, and isokinetic dynamometer (PRIMUS RS, BTE, USA) was used to measure the power and velocity error during knee extension. The collected data was analyzed using a Pearson test and SPSS 21.0. The correlation between PE and VE according to the condition and frequency of feedback on each phase during knee extension was significant. Both PE and VE were significantly higher when the feedback was provided with high frequency, passive, and no feedback. Our study suggests that application of SCF can help to improve the proprioception of the healthy person while reducing errors through low frequency and active feedback.

기계식 이음 PE관의 응답변위법 기반 내진성능평가 요령 (Seismic Performance Evaluation of Mechanically Jointed PE Pipeline by Response Displacement Method)

  • 박동순
    • 한국구조물진단유지관리공학회 논문집
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    • 제27권4호
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    • pp.23-32
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    • 2023
  • 지진 시 매설 PE관은 파단시 신장율이 우수하여 상대적으로 우수한 내진성능을 보이는 것으로 보고되고 있다. 국내 융착식 PE관의 응답변위법 기반 내진성능평가 절차를 제안한 바 있으나, 기계식 이음 PE관에 대한 절차는 부재한 실정이다. 이에 본 연구에서는 기계식 이음 PE관의 응답변위법 기반 내진성능평가 절차를 제시하였다. 기계식 이음 PE관의 경우 분절관의 평가 절차를 따르며, 관체 발생응력, 이음부 신축변형률 및 이음부 휨 각도 평가를 수행하도록 제안하였다. 또한 지반의 축방향 변형률 산정에 필요한 지반의 불균질성 계수를 도입하였다. 지반 액상화 우려가 있는 지반에 대한 측방 변위 및 재압밀 침하량 계산 방법도 함께 제안하였다. 국내 지반 환경을 고려한 민감도 해석 결과, 일정 품질이 확보된 기계식 이음 PE관은 지반 액상화를 고려하지 않을 때, 양호한 구조적 지진 안전성을 보였다. 본 절차는 주로 소규모 관경의 배관 접합에 사용하는 기계식 접합 매설 PE관의 내진설계 및 내진성능평가에 활용할 수 있을 것으로 판단된다.

Low Temperature Plasma-Enhanced Atomic Layer Deposition Cobalt

  • 김재민;김형준
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2009년도 추계학술발표대회
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    • pp.28.2-28.2
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    • 2009
  • Cobalt thin film was fabricated by a novel NH3-based plasma-enhanced atomic layer deposition(PE-ALD) using Co(CpAMD) precursor and $NH_3$ plasma. The PE-ALD Co thin films were produced well on both thermally grown oxide (100 nm) $SiO_2$ and Si(001) substrates. Chemical bonding states and compositions of PE-ALD Co films were analyzed by XPS and discussed in terms of resistivity and impurity level. Especially, we successfully developed PE-ALD Code position at very low growth temperature condition as low as $T_s=100^{\circ}C$, which enabled the fabrication of Co patterns through lift-off method after the deposition on PR patterned substrate without any thermal degradation.

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박피양파의 선도유지를 위한 포장조건 (Packaging Conditions of Peeled Onions to Preserve there Freshness)

  • 정순경;조성환
    • 한국식품저장유통학회지
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    • 제4권3호
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    • pp.259-264
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    • 1997
  • To improve freshness of onion(Allium cepa), it was packed with various packaging films and stored at 5$^{\circ}C$ until 52 days. During the storage, internal gas composition, weight loss, spout ratio, decay ratio, surface color were determined. The used packaging films are two-perforated LDPE (control), LDPE, CPP/OPP/PE, Nylon/PE and Ag-zirconium filled LDPE. Onions were prepared by peeling or dipping in GFSE(grape fruit seed extract) and packed under vacuum or atmosphere with the selective films. Anaerobic condition was shown in the Nylon/PE package after 4 days and, thus weight loss, sprout ratio and color were considerably poor. All onions in the vacuum package after 15 days were spouted. Onions in CPP/OPP/PE and functional film(Ag-zirconium filled LDPE) package showed aerobic respiration until 52 days. Thus, the quality of onions in these packages was superior to the control.

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Dry separation of PVC film from waste plastic film mixture using Air Table

  • Song, Young-Jun;Hiroki Yotsumoto;Eisetsu Oi
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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    • pp.734-737
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    • 2001
  • A study was conducted in order to remove PVC from the waste plastic film mixture. The fittings of Air Table was modified to increase the separation efficiency of PVC. By using the improved air table, the PE and PVC was successfully separated from PVC-PE film mixture with the yield of PE 90% or more and with the content of PVC in PE 1% or less. The detail of the separation condition and result will be discussed in this paper.

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Multidimensional Chromatography/Mass Spectrometry를 이용한 혼합 폐플라스틱의 열분해 오일 특성 평가에 관한 연구 (Study on Oil Production from Pyrolysis of Mixed Plastic Waste Using Multidimensional Chromatography)

  • 김석완
    • 한국환경과학회지
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    • 제11권4호
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    • pp.375-382
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    • 2002
  • The total hydrocarbon distribution of oil products obtained from the pyrolysis of four kinds of mixtures of polyethylene-polystyrene waste has been studied by multidimensional chromatography(high performance liquid chromatography followed by capillary gas chromatography)/mass spectrometry. Saturated, unsaturated and aromatic hydrocarbons in oil products were selectively pre-separated according to structural groups by HPLC and the weight fraction of each group was estimated by analysis of each component using GC-FID response factors. The hydrocarbon distribution of aliphatic fraction consists of $C_{5}$ to $C_{25}$ saturated and unsaturated hydrocarbons. And that of aromatics fraction consists of benzene, toluene, xylene, styrene, propenyl benzene, naphthalene, and some of derivatives. Pyrolysis temperature did not affect the ratio of total weight fraction of aliphatic over aromatic hydrocarbon distribution in case of PS only and PE-PS mixtures (1:1 and 1:4 wt. ratio) as a feed while affected the ratio of total wt. fraction in case of PE only. The optimal temperature for the maximum oil production was $600^{\circ}C$ for pyrolysis of PS and 1:1 and 1:4 mixtures of PE and PS. The optimal condition for aromatic recovery was $600^{\circ}C$ with 1:1 mixture of PE and PS. In this condition, aromatic was produced up to 90% of total oil product. The maximum yield of toluene, xylene, styrene, and propenyl benzene were 8.6, 8.9, 51.0 and 7.4% of feed for pyrolysis PS at $700^{\circ}C$, respectively. However, only 1.3% naphthalene was recovered at $700^{\circ}C$ with 1:1 PE:PS(by wt.).

적응추정자에 대한 파라메터 수렴속도의 해석 (Analysis of the Parameter Convergence Rate for an Adaptive Identifier)

  • Kim, Sung-Duck
    • 대한전기학회논문지
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    • 제38권2호
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    • pp.127-136
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    • 1989
  • This paper describes the parameter convergence properties of an adaptive system to identify a single-input single-output plant model. It is demonstrated that, by using power spectrum analysis, the persistency of excitation (PE) condition in order to guarantee the exponential stability of the adaptive control system can be transformed into the positive definite behavior for the auto-correlation function matrix of adaptive signal. The existence of parameter nominal values can be analyzed by this condition and the convergence rates of parameter are determined by examining the auto-correlation function. We may use the sufficient richness (SR) of input spectrum instead of the PE condition to analyze the parameter boundedness. It can be shown that the eigen values of the auto-correlation function are always related with adaptive gain, input amplitude and positions or numbers of input spectra. In each case, the variation of parameter convergence rate can be also verified.

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전자선을 이용한 PVDF-HFP/Silylated Al2O3가 코팅된 리튬 이차 전지용 폴리에틸렌 분리막의 전기화학적 특성 연구 (Electrochemical Study on PVDF-HFP/Silylated Al2O3-coated PE Separators using the Electron Beam Irradiation for Lithium Secondary Battery)

  • 손준용;신준화;노영창
    • 방사선산업학회지
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    • 제4권4호
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    • pp.359-364
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    • 2010
  • PVDF-HFP (binder)/silylated alumina (inorganic particle)-coated PE (polyethylene) separators were with various compositions of binder and inorganic particle were prepared by a dip-coating process with humidity control (R.H. 25% and 50%) using electron beam irradiation. The morphology of the coated PVDF-$HFP/Al_2O_3$ layer with various compositions of PVDF-HFP and $Al_2O_3$, and humidity condition was found to be an important factor in determining ionic conductivity of the prepared separators. The PVDF-$HFP/Al_2O_3$ (5/5)-coated PE separator prepared at R.H. 50% followed by electron beam irradiation at 200 kGy was applied for lithium-ion polymer battery and the cell test results showed improved high-rate discharge performance and better cyclic stability compared to the cells with the bare PE and the PVDF-HFP-coated PE separators.

초고속 용융 원심방사를 이용한 폴리에틸렌 마이크론 섬유의 제조 (Preparation of Polyethylene Micro-fibers by High Speed Centrifugal Melt Spinning)

  • 양성백;이정언;지병철;주남식;염정현
    • 한국염색가공학회지
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    • 제32권4호
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    • pp.239-244
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    • 2020
  • Polyethylene (PE) micro-fiber have been prepared at different hot air temperature (60, 80 and 100 ℃) and different pressure (20, 40, 60 and 80 kPa) by melt centrifugal spinning technique. The parameters of melting centrifugal spinning including polymer contents, rotational velocity, temperature of hot air and pressure were optimized for the fabrication process. The study showed that 8000 rpm rotational velocity, 80 ℃ heated hot air and 40 kPa air pressure are the best condition to obtain uniform and strong PE fiber. The prepared PE fibers were analyzed by field emission scanning electron microscope and universal testing machine and found that fibers with reduced diameter and improved tensile strength are obtained at hot air condition.