• Title/Summary/Keyword: residual time

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Using Mean Residual Life Functions for Unique Insights into Strengths of Materials Data

  • Guess Frank M.;Zhang Xin;Young Timothy M.;Leon Ramon V.
    • International Journal of Reliability and Applications
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    • v.6 no.2
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    • pp.79-85
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    • 2005
  • We show how comparative mean residual life functions (MRL) can be used to give unique insights into strengths of materials data. Recall that Weibull's original reliability function was developed studying and fitting strengths for various materials. This creative comparing of MRL functions approach can be used for regular life data or any time to response data. We apply graphical MRL's to real data from tests of tensile strength of high quality engineered wood.

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Study on the Formation of Residual Layer Thickness by Changing Magnitude and Period of UV Imprinting Pressure (UV임프린트 공정에서 임프린팅 가압력 및 가압시간에 따른 레진 잔막 두께형성에 대한 실험연구)

  • Shin, Dong-Hyuk;Jang, Si-Youl
    • Tribology and Lubricants
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    • v.26 no.5
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    • pp.297-302
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    • 2010
  • This study is focused on the resin layer formation of UV imprinting process by changing imprinting pressure and period. The mold shape is made for the process of window open over the pattern transfer area and the imprinting period is assigned as the time just before the UV light curing. The residual layer is measured by changing the imprinting period and pressure magnitude, and the measured data of residual layer provides useful information for the design of the process conditions of imprinting processes.

Stability of Ascorbic Acid in the Solutions of Sugars and Amino Acids (당질과 아미노산이 Ascorbic Acid 의 안정도에 미치는 영향)

  • Hwang, Hee-Za
    • Journal of Nutrition and Health
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    • v.15 no.1
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    • pp.22-29
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    • 1982
  • As sugar and amino acid were added to the ascorbic acid solution the content of ascorbic acid was quantitatively determined by 2, 4-dinitrophenyl hydrazine method. The residual ascorbic acid was shown to increase slightly when sorbose, rhamnose or mannose was added to the ascorbic acid solution whereas residual ascorbic acid was shown to decrease in time to the addition of other sugars. The effects of amino acid to the ascorbic acid solution were found that monoamino-mono, or dicarboxylic acids and aromatic amino acids increased the residual ascorbic acidity whereas diamino-monocarboxylic acids and sulfur containing amino acids decreased the residual ascorbic acidity.

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Sensitivity Analysis of input shaping filter designed in the Z-domain (Z-영역에서 설계된 입력성형필터의 민감도 해석)

  • Park, Un-Hwan;Lee, Jae-Won;Lim, Byoung-Duk
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.8
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    • pp.883-888
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    • 1999
  • To obtain high positioning auccuracy for a long, flex bleman Ipulator, residual vibration must be removed from the tip motion. But it is difficult to control the vibration of low frequency. There are open-loop and closed loop methods in the elimination of the residual vibration. We inroduce input shaping technique has been used as a simple open-loop method of controlling the residual vibration of a flexible manipulator. Design of input shaper in the continuous time domain is complicated. This paper presents a new technique that designs input shaper in the z-domain and analyzes input shaping method in the z-domain. This technique is simple and easy to design input shaper.

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Welding Residual Stresses Distribution Characteristics of High Tensile Steel for Ship Structures in Laser Welding (선체고장력강 레이저 용접부의 잔류응력분포 특성에 관한 연구)

  • 방한서;윤병현;김영표;임채환
    • Journal of Welding and Joining
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    • v.21 no.3
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    • pp.35-39
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    • 2003
  • Laser welding has good characteristics such as high density energy, high speed and short heating time, as compared with conventional arc welding. The joint of laser welding also has good mechanical characteristics in general. However, relevant research is not sufficient to understand laser welding in the view point of mechanics until a recent date. In this paper, numerical simulation has been conducted to analyze distribution of welding residual stresses. Welding residual stresses of specimen have been measured by using sectioning method to compare the results between simulation and experiment.

Determination of the Residual Stress Distribution along the Depth of Silicon by XRD $p^+$ Method (X선 회절법을 이용한 $p^+$ 실리콘 내 잔류응력의 깊이 방향 분포 추정)

  • Jung, O.C.;Yang, E.H.;Yang, S.S.
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.593-595
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    • 1995
  • X-Ray Diffraction method that gives direct information about the deformation of crystal lattice is used for the determination of profiles of the residual stress along the depth of heavily boron doped silicon. The residual stress distribution is obtained by XRD method as measuring the deformation of the front surface of the $p^+$ silicon layer fabricated through different etch time. It is determined that the compressive residual stress exists in the most region except the font surface.

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Study on Residual Stress in Viscoelastic Thin Film Using Curvature Measurement Method

  • Im, Young-Tae;Park, Seung-Tae;Park, Tae-Sang;Kim, Jae-Hyun
    • Journal of Mechanical Science and Technology
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    • v.18 no.1
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    • pp.12-19
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    • 2004
  • Using LSM (laser scanning method) , the radius of curvature due to thermal deformation in polyimide film coated on Si substrate is measured. Since the polyimide film shows viscoelastic behavior, i.e., the modulus and deformation of the film vary with time and temperature, we estimate the relaxation modulus and the residual stresses of the polyimide film by measuring the radius of curvature and subsequently by performing viscoelastic analysis. The residual stresses relax by an amount of 10% at 100$^{\circ}C$ and 20% at 150$^{\circ}C$ for two hours.

New Bootstrap Method for Autoregressive Models

  • Hwang, Eunju;Shin, Dong Wan
    • Communications for Statistical Applications and Methods
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    • v.20 no.1
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    • pp.85-96
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    • 2013
  • A new bootstrap method combined with the stationary bootstrap of Politis and Romano (1994) and the classical residual-based bootstrap is applied to stationary autoregressive (AR) time series models. A stationary bootstrap procedure is implemented for the ordinary least squares estimator (OLSE), along with classical bootstrap residuals for estimated errors, and its large sample validity is proved. A finite sample study numerically compares the proposed bootstrap estimator with the estimator based on the classical residual-based bootstrapping. The study shows that the proposed bootstrapping is more effective in estimating the AR coefficients than the residual-based bootstrapping.

Calibration of Contact Depth for Evaluating Residual Stress using Instrumented Indentation Testing (연속압입시험법을 이용한 원전구조물의 잔류응력 평가를 위한 접촉깊이의 보정)

  • Kim, Young-Cheon;Kang, Seung-Kyun;Ahn, Hee-Jun;Kim, Kwang-Ho;Kwon, Dongil
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.7 no.1
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    • pp.41-47
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    • 2011
  • Residual stress is the key parameter for reliability and lifetime assessment because it can reduce the fatigue strength and fracture properties of industrial structures. Recently, instrumented indentation testing (IIT) has been widely used for evaluating it, since it does not need specific specimen and time-consuming procedure. However, conventional Oliver-Pharr method, which is used for calibrating contact depth to analyze indentation load-depth curve, cannot estimate plastic pile-up between indenter and surface of specimen. Here, we introduce f parameter which is the ratio of contact depth and maximum depth, to consider pile-up height. And, its application for evaluating residual stress of weldment is introduced.

Residual Synchronization Error Elimination in OFDM Baseband Receivers

  • Hu, Xingbo;Huang, Yumei;Hong, Zhiliang
    • ETRI Journal
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    • v.29 no.5
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    • pp.596-606
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    • 2007
  • It is well known that an OFDM receiver is vulnerable to synchronization errors. Despite fine estimations used in the initial acquisition, there are still residual synchronization errors. Though these errors are very small, they severely degrade the bit error rate (BER) performance. In this paper, we propose a residual error elimination scheme for the digital OFDM baseband receiver aiming to improve the overall BER performance. Three improvements on existing schemes are made: a pilot-aided recursive algorithm for joint estimation of the residual carrier frequency and sampling time offsets; a delay-based timing error correction technique, which smoothly adjusts the incoming data stream without resampling disturbance; and a decision-directed channel gain update algorithm based on recursive least-squares criterion, which offers faster convergence and smaller error than the least-mean-squares algorithms. Simulation results show that the proposed scheme works well in the multipath channel, and its performance is close to that of an OFDM system with perfect synchronization parameters.

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