• Title/Summary/Keyword: characteristics curve

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Evaluation of J-R Curve for Aluminum 5083 Alloy Weldment by Load Ratio Analysis (Load Ratio 해석에 의한 알루미늄 5083 합금 용접부의 J-R곡선 평가)

  • 윤한기;김연겸
    • Journal of Welding and Joining
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    • v.15 no.4
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    • pp.178-186
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    • 1997
  • The purpose of this study is to evaluate the J-R curve characteristics for the 5083 aluminum alloy weldment by the load ratio analysis. The results of the load ratio analysis are compared with those of the J-R curve which are obtained by the ASTM unloading compliance method. The crack length calculated by the load ratio analysis is agrees well with the measured final crack length. The slope of the exponential J-R curve estimated by the load ratio analysis is slightly smaller than that by the ASTM unloading compliance method. The exponential correlation of the J-R curve for the 5083 aluminum alloy base metal by the load ratio analysis is J = 93.88 ${\Delta}{\alpha}^{0.375}$. That for the weld metal and HAZ is J = 69.87 ${\Delta}{\alpha}^{0.389}$ and J = 70.59 ${\Delta}{\alpha}^{0.359}$ respectively. The J-R curve obtained by the ASTM unloading compliance method is overpredicted and should be offsetted due to the initial negative crack. On the other hand, the load ratio analysis method can evaluate the J-R curve by only load displacement curve without particular crack measurement equipment.

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A Study on the Optimal Design of Automotive Cam Profiles using Hermite Curve (Hermite 곡선을 이용한 자동차 엔진 캠 형상의 최적 설계에 관한 연구)

  • 김도중;김원현
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.4
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    • pp.129-140
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    • 1998
  • A numerical method is proposed to optimize automotive cam profiles. An acceleration curve of a cam follower motion is described by Hermite spline curves. Because of the intrinsic characteristics of the Hermite curve, it is possible to design an acceleration curve with arbitrary shape. Design variables in the optimization problem are location of control points which define the acceleration curve. Objective function includes dynamic performances as well as kinematic properties of a valve train. Similar optimization procedure was also performed using Polydyne cam profile synthesis method. Optimized profiles using the Hermite curve are proved to be superior to those using the Polydyne method.

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Water Quality Characteristics Evaluation by Flow Conditions Using Load Duration Curve - in Youngbon A Watershed - (부하지속곡선을 이용한 유량 조건별 수질특성 평가 - 영본A 유역을 대상으로 -)

  • Park, Jinhwan;Kim, Kapsoon;Jung, Jaewoon;Hwang, Kyungsup;Moon, Myungjin;Ham, Sangin;Lim, Byungjin
    • Journal of Environmental Impact Assessment
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    • v.22 no.4
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    • pp.319-327
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    • 2013
  • This study was conducted to identify runoff characteristics of pollutants using flow duration curve(FDC) and load duration curve(LDC) in Youngbon A watershed during 2009~2011. A flow rate and pollutant load in the study watershed were estimated by equation of stage-discharge and discharge-loads rating curve. From these methods, BOD, T-N, and T-P have evaluated whether water quality standards would have attained. Results showed that BOD loads of about 50% plotted above the LDC, while T-N and T-P loads of about 50% plotted below the curve. It means that BOD of about 50% have exceeded the water quality criteria, while T-N and T-P of about 50% have complied with the water quality standards. Meanwhile, BOD, TN and T-P loads plotted above the LDC of low flows, implying that they were more affected by point pollution sources than nonpoint pollution sources in the study watershed.

Validity Examination on Evaluation of J-R Curve in the Nuclear Reactor Pressure Vessel Steels and Aluminum Alloys by Load Ratio Analysis (원자로 압력용기강 및 Al 합금재의 J-R곡선평가시 Load Ratio 해석의 유효성 검토)

  • Yoon, H.K.;Woo, D.H.;Kim, Y.K.;Cha, G.J.
    • Journal of Power System Engineering
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    • v.1 no.1
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    • pp.80-90
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    • 1997
  • The purpose of this study is to evaluate the validity examination of the J-R curve characteristics for the nuclear reactor pressure vessel steels and Al alloys by the load ratio analysis. The results of the load ratio analysis are compared with those of the J-R curve which are obtained by the ASTM unloading compliance method. The crack length calculated by the load ratio analysis is agree well with the measured final crack length. The slope of the exponential J-R curve estimated by the load ratio analysis is slightly smaller than that by the ASTM unloading compliance method. The J-R curve obtained by the ASTM unloading compliance method is over-predicted and should be offsetted due to the initial negative crack. On the other hand, the load ratio analysis method can evaluate the J-R curve by only load-displacement curve without particular crack measurement equipment.

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A Study on the Fabrication of Plasma Display Panel and It's Characteristics (플라즈마 디스플레이 판넬의 제작 및 특성 연구)

  • Kim, J.S.;Choi, K.C.;Shin, B.J.;Whang, K.W.
    • Proceedings of the KIEE Conference
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    • 1990.11a
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    • pp.157-160
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    • 1990
  • A dot matrix type DC Plasma Display Panel was fabricated and it's characteristics was investigated. Paschen curve and I-V curve of various gas mixture was given. Optimal gas mixing ratio, pressure and operating point was determined. The priming effect was observed and discharge delay time was measured with varing applied voltage, priming current, priming distance, duty ratio.

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The tensile characteristics of steel sheets at warm condition (박판의 온간상태에서의 인장특성)

  • 최치수
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.03a
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    • pp.49-52
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    • 1999
  • In the present study the tensile test was carried out for steel sheets to offer the database for the material characteristics at various temperature condition. The results are constructed with tensile strength total elongation Lankford vale and the flow curve and these can be employed usefully into the analyzing program as input data for the sheet metal forming processes at warm condition.

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Infiltration Characteristics for Unsaturated Residual Soil (화강풍화토의 불포화 침투특성에 관한 연구)

  • 김영욱;김도형;성상규;이인모
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.147-152
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    • 2001
  • This study investigated one-dimensional vertical infiltration to an unsaturated residual soil by numerical solutions, FDM. In order to estimate the parameters needed for numerical analysis, tire soil-water characteristic curve(SWCC) of Shinnae-dong soil, one of the most typical residual soils in Korea, were experimentally obtained. Then, the statistical analysis for obtaining the SWCC was performed. The numerical solution to the linearized governing equation for unsaturated groundwater flow provides the infiltration characteristics for the unsaturated residual soil represented by transient pressure profiles and water contents profiles.

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Context Dependent Feature Point Detection in Digital Curves (Context를 고려한 디지털 곡선의 특징점 검출)

  • 유병민;김문현;원동호
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.4
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    • pp.590-597
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    • 1990
  • To represent shape characteristics of digital closed curve, many algorithms, mainly based on local properties, have been proposed. In this paper, we propose a new algorithm for detecting local curvature maxima which reflects context, i.e., structural or surrounding regional characteristics. The algorithm does not require the value of k as an input parameter which is the major problem in k-curvature method in digital curve, but calculates it at each point depening on the context. The algorithm has been applied to two dimensional image boundaries. The efficiency of the algorithm is addressed by comparing the result of existing contest dependent algorithm.

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Recession Characteristics Analysis of Ssangchi Watershed (쌍치유역의 감수특성 분석)

  • 이재형;윤재민;이희주;박정인
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1999.10c
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    • pp.459-464
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    • 1999
  • The objective of this study is to analyze hydrologic recessiioon curve at the outlet of the ssangchi basin. For the development of recession equation, the initial discharge(Q0) and the recession parameters are estimated . It is shown that the accurate estimates of recession curve is easily obtained . The obtained parameters can be related to the basin characteristics, drainge area, and the total stream length so that they can be used for the development of the regional low flow estimation model.

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