• Title/Summary/Keyword: Phase-Type Distribution

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Micropolar thermoelastic medium with voids under the effect of rotation concerned with 3PHL model

  • Othman, Mohamed I.A.;Alharbi, Amnah M.;Al-Autabi, Al-Anoud M. Kh.
    • Geomechanics and Engineering
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    • v.21 no.5
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    • pp.447-459
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    • 2020
  • This paper aims to investigate the effect of rotation on a micropolar thermoelastic medium with voids problem. The problem is assessed according to three-phase-lag model. The normal mode analysis used to obtain the analytical expressions of the considered variables. The non-dimensional displacement, temperature, Micro rotation, the change in the volume fraction field, and stress of the material are obtained and illustrated graphically. Comparisons are made with the results predicted by two theories; namely three- phase-lag model (3PHL) and Green-Naghdi theory of type III (G-N III). The considered variables were plotted for different values of the rotation parameter, the phase-lag of heat flux and the phase-lag of temperature. The numerical results reveal that the rotation and the phase-lag times significantly influence the distribution of the field quantities. Some particular cases of interest are deduced from the present investigation.

A development of intelligent spacer built in the Internal type UHF partial discharge sensor (초고주파 광대역 부분방전 센서를 내장한 지능형 스페이서 개발)

  • Kim, Dong-Suk;Hwang, Chul-Min;Kim, Young-Noh;Choi, Jae-Ok;Seo, Wang-Byuk;Han, Bong-Soo;Choi, Soo-Hyun
    • Proceedings of the KIEE Conference
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    • 2007.11a
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    • pp.163-164
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    • 2007
  • In this study, we developed intelligent spacer built in the internal type UHF PD sensors. 3-Dimensional electro-magnetic simulations were performed to analyze electric-field distribution of the single-phase GIS and three-phase GIS. After considering the spacer's specification, Sensor structures were designed and analyzed using the 3-D EM Simulator. As a result of the simulation the internal type UHF PD sensors were built in. Performance of the sensor built into real scale GIS spacer was measured in terms of return loss and detected Max voltage. And we identified a character of the intelligent spacer by using 5pC partial discharge ceil.

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Classification of distribution channels of textile and apparel retailers in Turkey

  • Saricam, Canan;Erdumlu, Nazan
    • The Research Journal of the Costume Culture
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    • v.21 no.6
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    • pp.961-966
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    • 2013
  • Being one of the most important textile and apparel producers for years, Turkey began to become active in terms of retailing. Although retailing industry is in its growing phase, the social and economic influences caused the customers' tastes and demands to be more distinctive and segmented in parallel with the advancement of the retail industry. Therefore, the retail industry began to develop in more fragmented way where clear boundaries between different types of retailers were established. In this study, the apparel retail market is overviewed and analyzed within the context for determination of the current situation and future prospective. To this aim, the textile and apparel companies that are active in Turkey were classified into groups based on the type of distribution channels they used. Then, the performances of the groups were established using the secondary type of resources. Finally, the findings were summarized, by showing the similarities and differences between different channels.

Properties of Partial Discharge accompanying with Electrical Tree in LDPE (저밀도 폴리에틸렌에서 전기트리에 수반되는 부분방전의 특성)

  • 이광우;박영국;강성화;장동욱;임기조
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.234-238
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    • 1999
  • The correlation between shape of electrical trees and partial discharge(PD) pulses in low density polyethylene(LDPE) were discussed. We observed growth feature of electrical tree by using optical microscope. On the basis of experimental results of measurements of trees occurring in the needle-plane arrangement with needle shape void and without needle shape void , statistical quantities are derived, which are relevant to PD pulse amplitude and phase. The PD quantities detected by partial discharge detector. we were analyzed q-n distribution pattern and $\psi$ -q-n distribution pattern. In this experiment, electrical trees in the needle-plane arrangement with needle shape void propagated branch type tree and in the needle-plane arrangement without needle shape void propagated bush type tree

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Effect of the Groove Shape of Ultra Thick Box-Column with Center Segregation under High Heat Input for Corner Welding (중심 편석층이 있는 극후판 박스-칼럼의 대입열 코너이음 용접시 그루브 형상의 영향)

  • 최원규;이종봉;권영두;구남서
    • Journal of Ocean Engineering and Technology
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    • v.16 no.2
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    • pp.72-79
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    • 2002
  • In this study, time-dependent distributions of temperature and stresses, in the box-column welded from ultra thick plates with center segregation, has been analyzed by the commercial finite element package SYSWELD+, for several types and angles of groove. The major points of investigation are the optimum type and angle of groove that minimize weld stress specially at the center segregation, as well as temperature distribution, residual stresses and changes in the mechanical properties. The results can be summarized as follows; 1) Generally the thermal cycle at the root of groove exhibits relatively rapid cooling pattern, however, most of the other part weldment have a slow cooling pattern in all groove types. 2) Most of the micro-structures of weldment are composed of ferrite and pearlite, meanwhile we could find martensite and bainite locally a the root of the groove. 3) Optimum groove type for high heat input welding of box-column corner is a double groove type, and the optimum angle for the groove is 30~$45^{\circ}$ that minimize deformation and weld stress at the center segregation.

Ground Fault Current Variation of 22.9kV Multi Neutral Grounded Distribution System with CD Type Superconducting Cable (22.9kV 중성점 다중접지계통에 CD형 초전도케이블을 적용한 경우의 지락전류변화)

  • Lee, Jong-Bae;Hwang, Si-Dole;Sohn, Song-Ho;Lee, Geun-Joon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.6
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    • pp.993-999
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    • 2007
  • This paper discusses the effects of CD type superconducting cable operation in 22.9kV multi neutral grounded distribution system during L-G fault and counterplans to power system protection. In case of using the 3-phase CD-type superconducting cable, the inductance of superconducting cable system would be decreased due to the current of shield part of superconducting cable, which is opposite direction and nearly equal value with respect to main superconductor. However, when the shield circuit system is operated in shorted state, shield current decreases faulted ground current and give effects to power system protection scheme. This study examines the phenomena of single line to ground fault case in above mentioned system using the EMTDC program and discusses the right operation method of superconducting shield.

Numerical Simulation on the Performance of Axial Vane Type Gas-Liquid Separator with Different Guide Vane Structure

  • Yang, Fan;Liu, Ailan;Guo, Xueyan
    • International Journal of Fluid Machinery and Systems
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    • v.10 no.1
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    • pp.86-98
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    • 2017
  • In order to obtain high efficiency and low resistance droplet separation apparatus, axial vane type gas-liquid separators with different guide vanes were designed, and the RNG $k-{\varepsilon}$ model as well as discrete phase model (DPM) were used to investigate the flow pattern inside the separators. It was shown that the tangential velocity distribution under different guide vanes have Rankine vortex characteristics, pressure distribution exhibits a high similarity which value becomes big as the increase of the blade outlet angle and the decrease of the guide vane numbers. The increase of the guide vane numbers and the decrease of the blade outlet angle could make separation improve significantly. The separation efficiency is almost 100% when the droplet diameter is bigger than $40{\mu}m$.

Feasibility Test of LPG Vehicles by Using DME-LPG Blends (DME-LPG 혼합연료를 사용한 LPG 차량의 실증평가)

  • Youn, Jumin;Lee, Minho;Park, Cheonkyu;Hwang, Inha;Ha, Jonghan;Kang, Yong
    • Journal of Energy Engineering
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    • v.24 no.4
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    • pp.33-41
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    • 2015
  • Dimethyl ether (DME) can be used as a clean diesel alternative fuel due to the high cetane number and low emission, it can also be applied to automotive fuel as a blended liquefied petroleum gas (LPG) because physical properties are similar to those of LPG. In this study, feasibility test of LPG vehicle using blended DME-LPG fuel was investigated. Three types of fuel supply such as LPLi (Liquid phase LPG injection), LPGi (Liquid phase gas injection) and mixer type were selected to consider the LPG fuel-injection system. The performance characteristics of LPG vehicle were examined by using LPG and blended DME-LPG fuel in order to compare the exhaust emissions (CO, THC, $NO_X$) and fuel economy. The emissions and fuel economy of DME-LPG blend fuel were comparable to those of LPG with increasing driving distance.

TWO-CLASS M/PH,G/1 QUEUE WITH IMPATIENCE OF HIGH-PRIORITY CUSTOMERS

  • Kim, Jeongsim
    • Journal of applied mathematics & informatics
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    • v.30 no.5_6
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    • pp.749-757
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    • 2012
  • We consider the M/PH,G/1 queue with two classes of customers in which class-1 customers have deterministic impatience time and have preemptive priority over class-2 customers who are assumed to be infinitely patient. The service times of class-1 and class-2 customers have a phase-type distribution and a general distribution, respectively. We obtain performance measures of class-2 customers such as the queue length distribution, the waiting time distribution and the sojourn time distribution, by analyzing the busy period of class-1 customers. We also compute the moments of the queue length and the waiting and sojourn times.

Mother Wavelet Transform Suitable to Fault Method Algorism (고장 표정 알고리즘에 적합한 원형 웨이브릿 변환)

  • Park, In-Deok;Lee, Seung-Hwan;Kim, Si-Kyung
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.62_63
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    • 2009
  • This paper is distribution utility to generation of analysis fault several cases on the ground of substation in a energy meter three phase current, voltage data measurement to fault type and characteristics. Mother wavelet transformation of suitable to method algorism from the distribution utility to generation of fault in image impedance etc several parameter for utility characteristics effective to probatory.

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