• 제목/요약/키워드: Rolling Behavior

Search Result 330, Processing Time 0.03 seconds

First Experience: Citizens' Perception, Participation, and Evaluation of the New Legislative Electoral System in Taiwan

  • Yu, Ching-Hsin
    • Asian Journal for Public Opinion Research
    • /
    • v.1 no.1
    • /
    • pp.61-64
    • /
    • 2013
  • In 2008, Taiwan adopted a new mixed member system which is significantly different from the long-implemented SNTV-MMD system for the election of legislators. The new system cuts the number of legislative seats from 225 to 113, extends legislators' terms of office from three years to four, and most importantly, adopts a new mixed-member majoritarian (MMM) electoral system to replace the SNTV system for legislative elections. The election of legislators in 2008 was the first time that this new mixed electoral system was implemented in Taiwan. Mainstream literature continues to discuss the electoral impact on political parties and candidates by the new system while citizens' knowledge of the new system and its concomitant effects on citizens' behavior receive less attention. Worse still, almost all of the literature assumes that voters were fully aware of the operation and impact of the new electoral system and cast their ballots wisely. The purpose of this paper is to explore citizen's perceptions, participation and evaluation of this new system.

A Study on the High Temperature Tensile Properties of Hyderiedrided Zircaloy-4 (수소화시킨 지르칼로이-4의 고온인장성질에 관한 연구)

  • 조열래;정해용;김인배
    • Journal of the Korean institute of surface engineering
    • /
    • v.23 no.1
    • /
    • pp.44-51
    • /
    • 1990
  • Effects of temperature on the tensile properties of annealed and hydirded Zircaloy-4 plate in which hydrides are precitated paralled to the rolling direction were investigated. The main results obtained are as follows : 1) In annealed Zircaloy-4, yield point phenomenon was found in the temperature range of $200-550^{\circ}C$, while in hydrided alloy the phenomenon was found in the range of $200-400^{\circ}C$. 2) The dynamic strain aging behavior was occurd in the temperature interval of 400-$550^{\circ}C$in both annealed and hydrided Zircaloy-4. 3) The nearly values of yield strength, tensile stength and elongation are obtained in both annealed and hydried Zircaloy-4. From this result, we are led to conclude that the hydrides which are preiptated parallel to the circumferenial direction of nucler fuel are not so harmful for tensile properties of the clad.

  • PDF

On Application of Optimization Scheme To Direct Numerical Analysis Of Slider

  • Hwang, Pyung;Khan, Polina;Pan, Galina
    • KSTLE International Journal
    • /
    • v.5 no.1
    • /
    • pp.23-27
    • /
    • 2004
  • The object of the present work is the numerical analysis of the computer hard disk slider. The pressure between slider and disk surfaces is calculated using the Boundary Fitted Coordinate System and Divergence Formulation for the nonlinear Reynolds' equation solution. The optimization scheme is applied to search for the steady state position of the slider. The simplified method is given for the case of the fixed inclined pad. The film thickness ratios and pitching and rolling angles are considered as alternative choice of the slider's coordinates. The behavior of the objective function for the Negative Pressure slider is studied in details. Methods of conjugate directions and feasible directions are applied.

High Temperature Wear Behavior of Inconel 690 Steam Generator tube (인코벨 690 증기발생기 세관의 고온 마모 거동)

  • 홍진기;김인섭;김형남;장기상
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 2001.11a
    • /
    • pp.59-62
    • /
    • 2001
  • Flow induced vibration in steam generators has caused dynamic interactions between tubes and contacting materials resulting in fretting wear . Series of experiments have been performed to examine the wear properties of Inconel 690 steam generator tubes in various environmental conditions. For the present study, the test rig was designed to examine the fretting wear and rolling wear properties in high temperature(room temperature - 290。C) water. The test was performed at constant applied load and sliding distance to investigate the effect of test temperature on wear properties of the steam generator tube materials. To investigate the wear mechanism of material, the worn was observed using scanning electron microscopy. The weight loss increase at higher test temperature was caused by the decrease of water viscosity and the mechanical property change of tube material. The mechanical property changes of steam generator tube material, such as decrease of hardness or yield stress in the high temperature tests. From the SEM observation of worn surfaces, the severe wear scars were observed in specimens tested at the higher temperature.

  • PDF

Study on the Elliptical Elastohydrodynamic Lubrication in the Toroidal Continuously Variable Transmission (가변 동력전달 장치에서의 타원 형상 점접촉 탄성유체윤활 연구)

  • 장시열
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 2001.11a
    • /
    • pp.310-315
    • /
    • 2001
  • The most general feature of contact zone among the mechanical components is elliptical circle. In particular, continuously variable transmission (CVT) of toroidal type has elliptical shape of contact zone under the elastohydrodynamic lubrication condition, where the power is transmitted by the shearing the efluid. Due to the traction of the shear behaviors of lubricant over the small elliptical contact zone, high power of torque is transmitted. During the power transmission, many kinds of mechanical movements occur such as squeezing, sliding, rolling and spinning. The spinning effect that is not common contact behavior in tribological components frequently makes significant abnormal wear damage. In this work, the analysis of elliptical contact of elastohydrodynamic lubrication with spin effect is performed, which will give very useful information to understand the traction behaviors in toroidal type of CVT system.

  • PDF

Reliability Analysis of Slab Transfer Equipment in Hot Rolling Furnace (열간압연 가열로 슬라브 이송장치 신뢰도 해석)

  • Bae, Young-Hwan
    • Journal of the Korean Society of Safety
    • /
    • v.21 no.1 s.73
    • /
    • pp.6-14
    • /
    • 2006
  • The development of automatic production systems have required intelligent diagnostic and monitoring functions to overcome system failure and reduce production loss by the failure. In order to perform accurate operations of the intelligent system, implication about total system failure and fault analysis due to each mechanical component failures are required. Also solutions for repair and maintenance can be suggested from these analysis results. As an essential component of a mechanical system, a bearing system is investigated to define the failure behavior. The bearing failure is caused by lubricant system failure, metallurgical deficiency, mechanical condition(vibration, overloading, misalignment) and environmental effects. This study described slab transfer equipment fault train due to stress variation and metallurgical deficiency from lubricant failure by using FTA.

Effect of Aluminium and Boron on Formability for Cu Bearing Extra Low Carbon Steel Sheets (Cu첨가 극저탄소 고 강도강의 가공성에 미치는 Al과 B의 영향)

  • Kim, S.I.;Chung, K.H.;Hong, M.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2009.05a
    • /
    • pp.302-305
    • /
    • 2009
  • This paper examines the effect of nitride formation on formability for Cu bearing high strength extra low carbon (ELC) steel sheets. For this purpose, we have investigated the effect of addition of aluminium (Al) and boron (B) on texture and precipitation behavior of the ELC steel during continuous annealing. Mechanical properties and microstructures of the ELC steel sheets were analyzed as well using uni-axial tensile test, electron back-scattered diffraction (EBSD) technique and transmission electron microscopy (TEM) following pilot rolling and continuous annealing. It has been found that the addition of Al and B increases the precipitation of AlN and BN. What is more, the scavange of solute nitrogen is effective in increasing the formability of the ELC steels. In addition, the Al and B addition improves the aging property of the ELC steel.

  • PDF

Compatibility Analysis of Wheel/Rail Profile on Conventional Railway (기존철도 차륜/레일형상의 적합성 분석)

  • Hur, Hyun-Moo;Seo, Jung-Won;Chung, Heung-Chai;Goo, Dong-Hoe
    • Proceedings of the KSME Conference
    • /
    • 2004.04a
    • /
    • pp.934-939
    • /
    • 2004
  • Railway wheel/rail contact conditions have an influence on dynamic behavior of rolling stock. If there are problems of incompatibility between wheel and rail, damages like wheel wear, wheel spalling, rail wear, etc are occurred. Especially wheel and rail profiles are important factor of vehicle curving performance, so compatibility study between wheel and rail has to be carried out preferentially, In this study, we have analyzed the compatibility between wheel and rail of KNR conventional line to improve the maintenance efficiency of wheel and rail. Thus we showed the results relating to wheel/rail geometric contact, vehicle running performances as the change of wheel/rail combination.

  • PDF

An analysis of the thermal behaviour on the spindle system for machine tools (공작기계용 주축계에 관한 열적거동 해석)

  • 고태조
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.5 no.4
    • /
    • pp.90-97
    • /
    • 1996
  • The thermal deformation of a machine tool spindle influences the performance of the manufacturing systems for precision products. In this research, thermal analysis of a high speed machine tool spindle with the rolling bearing and the built-in motor is carried out by using Finite Difference Method. The thermal boundary conditions describing the heat generation in the bearing and built-in motor are considered in the simulation. And various convective boundary conditions are assumed with the empirical formula in the references. From the simulation results, the characteristics of each element affecting the dynamic thermal behaviour of the machine tool spindle system have been clarified. Therefore, this model can be well applied to the future development of the high speed spindle systems.

  • PDF

Knowledge based configuration design of a train vehicle body using CATIA (CATIA를 활용한 철도차량 차체 지식기반 형상설계)

  • Hwang Ho-Yon;Lee Jae-Young;Yang Doh-Chul;Kwon Tae-Soo;Jung Hyun-Seung
    • Proceedings of the KSR Conference
    • /
    • 2005.11a
    • /
    • pp.362-369
    • /
    • 2005
  • In this paper, a research for the knowledge based configuration design software development of a train vehicle has been presented. Parametric design and knowledge based design concepts have been introduced for rapid design changes and analyses using a commercial CAD software, $CATIA^{/circledR}$ Knowledgeware module. Positions and dimensions of door, small window, large window, and number of seats were used as design parameters. It is crucial for train vehicle design because it enables rapid conceptual design by instant configuration changes. The results of this research can be used as one sub module of the multidisciplinary train vehicle design software and provide a basic data for rolling stock behavior and driver cab ergonomics of a train vehicle.

  • PDF