• Title/Summary/Keyword: Moment prior

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Estimation of Plastic Bending Moment of Offshore Pipelines (해저관로의 대변형 굽힘에 의한 소성 모멘트 추정)

  • 이종현;최한석;이승건
    • Journal of Ocean Engineering and Technology
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    • v.17 no.2
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    • pp.21-26
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    • 2003
  • The reel-lay method of submarine pipelines a continuous string of pipe coiled onto a reel. Assembly of this pipe that is string is accomplished onshore by welding, and nondestructive testing is carried out prior to coiling the pipe. The total length of pipes on the reel depends on the reel and pipe diameters. Pipeline installation is accomplished by uncoiling, straightening the pipe, and laying out the pipe string onto the seabed as the barge moves forward. Installation associated with coiling and uncoiling is related to the bending moment and strain relationship of the pipeline, A highgrade pipe material is required when the reel-lay method is used. This paper is concerned with the highly plastic bending moment of the pipeline, including the effect of ovality. Moment calculation in the pipe is accomplished by the numerical method, including the variable ovalities during the plastic bending of the pipe string. The new calculation method of the high plastic bending moment was applied to the reel-lay method.

Factors governing redistribution of moment in continuous prestressed concrete beams

  • Kodur, V.K.R.;Campbell, T.I.
    • Structural Engineering and Mechanics
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    • v.8 no.2
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    • pp.119-136
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    • 1999
  • The failure load of a continuous prestressed concrete beam depends partially on the amount of redistribution of moment that occurs prior to failure. Results from a parametric study, carried out using a nonlinear finite element computer program, are presented to demonstrate the influences of various factors on redistribution of moment in two-span, continuous bonded prestressed concrete beams. Trends in the data from the numerical studies are compared with those from a theoretical expression for percentage of redistribution, and it is shown that the redistribution of moment occurring in a continuous prestressed concrete beam is a function of number of parameters.

A Force/Moment Direction Sensor and Its Application in Intuitive Robot Teaching Task

  • Park, Myoung-Hwan;Kim, Sung-Joo
    • Transactions on Control, Automation and Systems Engineering
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    • v.3 no.4
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    • pp.236-241
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    • 2001
  • Teach pendant is the most widely used means of robot teaching at present. Despite the difficulties of using the motion command buttons on the teach pendant, it is an economical, robust, and effective device for robot teaching task. This paper presents the development of a force/moment direction sensor named COSMO that can improve the teach pendant based robot teaching. Robot teaching experiment of a six axis commercial robot using the sensor is described where operator holds the sensor with a hand, and move the robot by pushing, pulling, and twisting the sensor in the direction of the desired motion. No prior knowledge of the coordinate system is required. The function of the COSMO sensor is to detect the presence f force and moment along the principal axes of the sensor coordinate system. The transducer used in the sensor is micro-switch, and this intuitive robot teaching can be implemented at a very low cost.

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Analytical Theory of Ball Bearing Considering Waviness of Rolling Elements (구름요소의 Waviness 를 고려한 볼베어링 해석 이론)

  • 정성원;장건희
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.7
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    • pp.275-286
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    • 2001
  • The research presents an analytical theory to calculate the characteristics of the bal bearing with waviness in its rolling elements considering the centrifugal force and gyroscopic moment of bal. The effects of centrifugal force and gyroscopic moment are introduced to the kinematic constraints and force equilibrium equations. and the waviness of rolling elements is modeled by sinusoidal function to calculate the contact force at each ball. The numerical solutions of governing equation of berating due to waviness are calculated by using the Newton-Raphson method. The accuracy of the research is validated by comparing the contact force. contact angle in case of considering the centrifugal force and gyroscopic moment of bal and the contact force and vibration frequencies in cases of considering waviness with the prior researches respectively. It investigates the stiffness, contact force. displacement and vibration frequencies of the ball bearing considering not only the centrifugal force and gyroscopic moment of ball but also the waviness of the rolling elements.

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Parametric Empirical Bayes Estimation of A Constant Hazard with Right Censored Data

  • Mashayekhi, Mostafa
    • International Journal of Reliability and Applications
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    • v.2 no.1
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    • pp.49-56
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    • 2001
  • In this paper we consider empirical Bayes estimation of the hazard rate and survival probabilities with right censored data under the assumption that the hazard function is constant over the period of observation and the prior distribution is gamma. We provide an estimator of the first derivative of the prior moment generating function that converges at each point to the true value in $L_2$ and use it to obtain, easy to compute, asymptotically optimal estimators under the squared error loss function.

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Load Measurements of 100 kW Wind Turbine (100 kW급 풍력발전기의 하중 측정)

  • Bae, Jae-Sung;Kim, Sung-One;Kyong, Nam-Ho
    • Journal of the Korean Solar Energy Society
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    • v.24 no.4
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    • pp.27-33
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    • 2004
  • Mechanical load measurements on blade and tower of Vestas 100 kW wind turbine has been reformed in Wollyong test site, Jeju island. The experimental procedure for the measurement of wind turbine loads, such as edgewise(lead-lag) bending moment, flapwise bending moment, and tower base bending moment, has been established. The test facilities consisting of strain-gauges, telemetry and T-Mon system are installed in the wind turbine. Strain gauges are on-site calibrated against load cell prior to monitoring the wind turbine loads. Using the test setup, the loads on the components are being measured and analysed for various external conditions of the wind turbine. A set of results for near rated wind speed has been presented in this paper.

Performance Monitoring and Load Analysis of Wind Turbine (풍력발전기의 성능 모니터링 및 하중분석)

  • Bae, Jae-Sung;Kim, Sung-One;Youn, Joung-Eun;Kyung, Nam-Ho
    • 유체기계공업학회:학술대회논문집
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    • 2004.12a
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    • pp.385-389
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    • 2004
  • Test facilities for the wind turbine performance monitoring and mechanical load measurements are installed in Vestas 100 kW wind turbine in Wollyong test site, Jeju island. The monitoring system consists of Garrad-Hassan T-MON system, telemetry system for blade load measurement, various sensors such as anemometer, wind vane, strain gauge, power meter, and etc. The experimental procedure for the measurement of wind turbine loads, such as edgewise(lead-lag) bending moment, flapwise bending moment, and tower base bending moment, has been established. Strain gauges are on-site calibrated against load cell prior to monitoring the wind turbine loads. Using the established monitoring system, the wind turbine is remotely monitored. From the measured load data, the load analysis has been performed to obtain the load power spectral density and the fatigue load spectra of the wind turbine.

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Analysis of demountable steel and composite frames with semi-rigid bolted joints

  • Wang, Jia;Uy, Brian;Li, Dongxu
    • Steel and Composite Structures
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    • v.28 no.3
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    • pp.363-380
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    • 2018
  • This paper presented an integral design procedure for demountable bolted composite frames with semi-rigid joints. Moment-rotation relationships of beam-to-column joints were predicted with analytical models aiming to provide accurate and reliable analytical solutions. Among this, initial stiffness of beam-to-column joints was derived on the basis of Timoshenko's plate theory, and moment capacity was derived in accordance with Eurocodes. The predictions were validated with relevant test results prior to further applications. Frame analysis was conducted by using Abaqus software with material and geometrical nonlinearity considered. Variable lateral loads incorporating wind actions and earthquake actions in accordance with Australian Standards were adopted to evaluate the flexural behaviour of the composite frames. Strength and serviceability limit state criteria were utilized to verify configurations of designed models. A wide range of frames with the varied number of storeys and bays were thereafter programmed to ascertain bending moment envelopes under various load combinations. The analytical results suggest that the proposed approach is capable of predicting the moment-rotation performance of the semi-rigid joints reasonably well. Outcomes of the frame analysis indicate that the load combination with dead loads and live loads only leads to maximum sagging and hogging moment magnitudes in beams. As for lateral loads, wind actions are more crucial to dominate the design of the demountable composite frames than earthquake actions. No hogging moment reversal is expected in the composite beams given that the frames are designed properly. The proposed analysis procedure is demonstrated to be a simple and efficient method, which can be applied into engineering practice.

The Influence of the Car Master's Recognized Core Capability level in Achieving Customer Satisfaction: Emphasis on Mediating Effect of Moment of Truth Quality (카마스터의 지각된 핵심역량 수준이 고객만족에 미치는 영향: 고객접점(MOT)품질의 매개효과를 중심으로)

  • An, Seong-Beom;Song, In-Am;Hwang, Hee-Joong
    • Journal of Distribution Science
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    • v.11 no.4
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    • pp.37-49
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    • 2013
  • Purpose - This research identifies the meaning of the core capability level of Car Master and the reason why its service at the Moment of Truth should be demonstrated through empirical cases. It can be seen that this study differs from existing research because it proposes that the recognized core capability level to achieve customer satisfaction should focus on the mediating effect of Moment of Truth quality. This paper examines the effect of Car Master's recognized core capability level on customer satisfaction by using the variables mentioned above. Moreover, this study uses regression analysis to verify that the mediating effect of Moment of Truth quality on Car Master's capability level achieves customer satisfaction. Research design, data, and methodology - First, we present evidence that could apply to Car Master's recognized core capability level by detailing the relationship between customer satisfaction and a structuring factor for Car Master's core capability level. Our proposed research model observes the relationship between the structuring factor of core capability and customer satisfaction. Second, we had an opportunity to define how the core capability and Moment of Truth quality affect customer satisfaction by performing empirical analysis on the partial mediating effect of Moment of Truth quality at a recognized core capability level and Moment of Truth quality affecting customer satisfaction. Results - First, the results indicate that Car Master's recognized core capability level (product professionalism, marketing skill, and reliability) positively affects customer satisfaction. Second, the results show that an ability to listen and a sense of dedication positively affect customer satisfaction, and are among the Moment of Truth quality factors; but performance capability, which is one of the Moment of Truth quality factors, does not positively affect customer satisfaction. These results clearly differ from prior studies focused on Moment of Truth quality and consumer satisfaction. Third, the results show that Moment of Truth quality has a partial mediating effect in terms of the impact of Car Master's recognized core capability level in achieving consumer satisfaction. Conclusions - This research indicates that the company will be able to expand if they investigate and show an interest in more training and education for Car Master. The study verified that outstanding Car Masters show differentiated performance on customer satisfaction at the Moment of Truth in various instances. Thus, we believe that this is the time for a discussion on systematic and empirically recognized core capability levels and the Moment of Truth quality. The study on Car Master's recognized core capability level offers suitable solutions for Car Masters to respond to customers at the Moment of Truth. Further, this study emphasizes the importance of service as a critical factor having a direct relationship with the company's success and failure and contributing to building trust with the customer. Thus, an investment in continuous education and training for Car Master will help the growth of the business.

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Objective Bayesian Estimation of Two-Parameter Pareto Distribution (2-모수 파레토분포의 객관적 베이지안 추정)

  • Son, Young Sook
    • The Korean Journal of Applied Statistics
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    • v.26 no.5
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    • pp.713-723
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    • 2013
  • An objective Bayesian estimation procedure of the two-parameter Pareto distribution is presented under the reference prior and the noninformative prior. Bayesian estimators are obtained by Gibbs sampling. The steps to generate parameters in the Gibbs sampler are from the shape parameter of the gamma distribution and then the scale parameter by the adaptive rejection sampling algorism. A numerical study shows that the proposed objective Bayesian estimation outperforms other estimations in simulated bias and mean squared error.