• Title, Summary, Keyword: End effect

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Signal Analysis of Motor Current for End Point Detection in the Chemical Mechanical Polishing of Shallow Trench Isolation with Reverse Moat Structure

  • Park, Chang-Jun;Kim, Sang-Yong;Seo, Yong-Jin
    • KIEE International Transactions on Electrophysics and Applications
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    • v.2C no.5
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    • pp.262-267
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    • 2002
  • In this paper, we first studied the factors affecting the motor current (MC) signal, which was strongly affected by the systematic hardware noises depending on polishing such as pad conditioning and arm oscillation of platen and recipe, head motor. Next, we studied the end point detection (EPD) for the chemical mechanical polishing (CMP) process of shallow trench isolation (STI) with reverse moat structure. The MC signal showed a high amplitude peak in the fore part caused by the reverse meal. pattern. We also found that the EP could not be detected properly and reproducibly due to the pad conditioning effect, especially when conventional low selectivity slurry was used. Even when there was no pad conditioning effect, the EPD method could not be applied, since the measured end points were always the same due to the characteristics of the reverse moat structure with an open nitride layer.

Effect of Stem Design on Contact Pressure and Stress Distribution of End-of-stem in Revision TKR (슬관절 재전치환술용 경골 삽입물 형상이 주대 말단부의 접촉압력과 응력 분포에 미치는 영향)

  • Kim, Yoon-Hyuk;Kwon, Oh-Soo;Park, Si-Mon
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.11
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    • pp.126-134
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    • 2006
  • In this study, the effect of stem-end design on contact pressure and stress distribution in revision TKR was investigated using finite element method. The finite element model of tibia, including the cortical bone, the cancellous bone and canal, was developed based on CT images. The implant models with various stem lengths, diameters, friction coefficients, and press-fit effects were considered. The results showed that the longer stem length, the stronger press-fit, the bigger stem diameter, and the higher friction coefficient increased both peak contact pressure and Von-Mises stress distributions. The results supported the clinical hypothesis that peak contact pressure and stress are related to the stem end pain. The results of this study will be useful to design the stem and reduce the end-of-stem pain in revision TKR.

A Study on Rear-End Designs for Effective Hydrodynamic Performance of Shroud Diffusers (슈라우드 디퓨져의 효과적인 유동을 위한 후단 형상의 연구)

  • Lee, Sang-Yul;Cho, Dae-Hwan
    • Journal of the Korean Society of Mechanical Technology
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    • v.19 no.3
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    • pp.299-305
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    • 2017
  • The diffuser is effective in closed systems, however, its effect is weaken in open or free flow situations. This can be solved by modifying the rear-end of the diffuser in a manner that enables the formation of strong vortex. By doing that, a large portion of fluid's energy is converted to vortex's dynamic energy, which results in the deduction of static component, or in other words, the decrease of pressure. This study involved the design of rear-end part for efficient hydrodynamic performance of shroud diffusers, and demonstrated with numerical simulation by computational fluid dynamics (CFD). This study focuses on the use of brim end for the shroud where the effect of brim's length and attaching angle are analyzed.

Effect of a Radio-frequency/Vacuum plus Press Drying Process of Some Hardwood Veneers for Decoration on Checking and End Waving (압체고주파진공건조에 의한 주요 활엽수 무늬목 단판의 이할과 끝말림 예방효과)

  • 이남호;최준호;정희석
    • Journal of the Korea Furniture Society
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    • v.10 no.2
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    • pp.29-36
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    • 1999
  • During a radio-frequency/vacuum plus press drying process of some hardwood veneers for decoration we investigated the effect of a grain and thickness of a veneer sheet on drying rates, variations of final moisture content within a bundle of veneer sheets, and formation of checking, end waving, and burning mark. About thirty three hundreds sheet of veneer could be dried in sixty five hours from green to in0-use moisture content, and a final moisture content was significantly effected by initial moisture content of veneer. There were nearly variations in a final moisture content among the veneer sheets in the same bundle. A checking was never found in a edge-sliced veneer, and very slight in a flat-sliced veneer of ash and red oak. There were no end waving and no burning mark in all veneer sheets.

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A Study Vibration Characteristic of Railway Freight Car's End Beam for Taebaek Line (태백선을 주행하는 화차 엔드빔의 진동특성에 관한 연구)

  • 함영삼;문경호;홍재성;이동형;서정원
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.378-383
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    • 2004
  • Bogie is the connection device between carbody and wheel. It is the core part that exert a important effect on the passenger safety and running safety. Bogie largely consist of bogie frame, suspension, brake, wheel set. Static and Dynamic load have acted on it complexly. So when the bogie is designed, finite element method, static load test, fatigue test running test should be considered. Some bogie frame of high speed railway freight car have the problem. It's end beam was cracked. The crack of the end beam have a bad effect on brake system. ROTEM co. made an improved end beam and applied one set to freight car. this report showed the vibration characteristic which was compared conventional bogie to improved bogie for running safety.

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Empirical Evidence on Closed-End Mutual Fund Discounts (폐쇄형 투자신탁회사의 할인현상에 관한 실증연구)

  • Kim, Chang-Soo
    • The Korean Journal of Financial Management
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    • v.13 no.1
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    • pp.311-340
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    • 1996
  • This paper investigates the determinants of discounts on closed-end mutual funds. Empirical tests on a panel of closed-end mutual funds show that the magnitude of discounts seems to be unequal for different types of funds. I find strong evidence on tax-timing option effect even after controlling for other variables which have been theorized to be important in determining discounts on closed-end mutual funds. Also, the uncertainty about the value of underlying assets in the fund's portfolio has a significant influence on discounts.

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The analysis of performance characteristics of a L.I.M with taken into consideration of end effect(II) -eddy current & air-gap flux density- (단부교리를 고려한 L.I.M의 동작특성 해석(II))

  • 임달호;장석명
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.36 no.4
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    • pp.240-251
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    • 1987
  • In this paper, with the end effect taken into consideration, the fundamental characteristics of a linear induction motor-the eddy currents of the secondary conducting sheet (traveller), the flux density in the air gap-are analysed by means of electromagnetic field theory. Accordingly, the derived governing eqations of the chatacteristics with goodness factor, presents that it was possible not only to predict the performance characteristics, but to obtain the data that needs to optimize a design of a motor with the reduction of the end effect.

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The Vector Control of SLIM Considering End-effect (단부효과를 고려한 편측형 선형유도전동기 벡터제어)

  • 조금배;임홍우;장용해;백형래
    • The Transactions of the Korean Institute of Power Electronics
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    • v.7 no.4
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    • pp.395-403
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    • 2002
  • The advanced space vector PWM is Implemented for the control system using high arithmetic performance microprocessor such as DSP. It is difficult to realize the complicate SLIM which is applied to SVPWM system, but widely used in vector control system or servo control system for AC motor because of its high performance in current control. In this paper, we use the dynamic characteristic analyzing method that can calculate efficiently the end effect by using equivalent circuit methode in the operating SLIM system modeling and examine the dynamic characteristics of SVPWM with PI controller.

Static Characteristics of Electrodynamic Maglev System (반발식 자기부상열차의 정특성해석)

  • 홍순흠;이양수;차귀수;한송엽
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.43 no.7
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    • pp.1067-1074
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    • 1994
  • This paper deals with the combined levitation and guidance EDS(Electrodynamic Suspension) Maglev system. Levitation and guidance forces generated in figured-of-eight coil are examined. End effect of Superconducting magnets is considered in that the air gap flux has been calculated using the finite number of magnets. Induced emfs and currents of ground coils are given as results. Eletromagnetic forces vary according to the built-in position of magnets. Levitation forces of the first magnet pair are the smellest and those of the second one are the largest. This result shows that the end effect of SCMs should be considered in a concentrated magnet system.

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A Study on the Problem of Permanent Magnet Linear Synchronous Motor According to End Effect (영구자석형 선형동기전동기의 단부효과에 의한 문제점 연구)

  • Kim, Duk-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.12
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    • pp.71-77
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    • 2010
  • A discontinuity of magnetic circuits according to the end effect is generated in PMLSM. And magnetic state of the 3 phase coils becomes unbalanced. Due to the unbalanced magnetic state, the unbalanced flux linkage, back electro-magnetic force and inductance of the 3 phase coils appear. In result, the circulating current is generated by unbalanced inductance even if the input voltages are in balanced state. Then the thrust and efficiency are decreased because of the circulating current. Therefore, in this paper, the unbalanced inductance and the thrust reduction according to discontinuity of magnetic circuits are analyzed by FEA(2D). To demonstrate the validity of the analysis results, the experiment results are compared with analysis results.