• Title/Summary/Keyword: Linear

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A Two-Axis Ultra-precision Stage Using Flexure-type Parallel Linear Guide Mechanism (플렉셔 구조의 병렬형 선형 안내기구를 이용한 2 축 초정밀 스테이지)

  • Choi Kee-Bong
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.1
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    • pp.129-135
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    • 2006
  • In this study, a two-axis ultra-precision stage driven by piezoelectric elements is presented. The stage has a flexure-type parallel linear guide mechanism consisting of quad-symmetric simple parallel linear springs and quad-symmetric double compound linear springs. While the simple parallel linear springs guide the linear motion of a moving plate in the stage, the double compound linear springs follow the motion of the simple parallel linear spring as well as compensate the parasitic motions caused by the simple parallel linear springs. The linear springs are designed by rectangular beam type flexures that are deformed by bending deflection rather than axial extension, because the axial extension is smaller than the bending deflection at the same force. The designed guide mechanism is analyzed by finite element method(FEM). Then two-axis parallel linear stage is implemented by the linear guide mechanism combined with piezoelectric elements and capacitance type displacement sensors. It is shown that the manufactured ultra-precision stage achieves 3 nm of resolution in x- and y-axis within 30 ${\mu}m$ of operating range.

A study on Parameters of Linear reservoir models (선형저수지 모형의 매개변수연구)

  • 고재웅;서영제
    • Water for future
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    • v.20 no.3
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    • pp.229-235
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    • 1987
  • The purpose of this study is to estimate the parameters of linear reservoir models in order to derive the Instantaneous unit hydrograph from a given small experimental watershed. The linear reservoir model is a conceptual model, consisting of cascade or parallel equal linear reservoirs, preceded by a linear channel which involved Nash, SLR(single linear reservoir) and 2-PLR(two-parallel linear Reservoir) model. the Nash model have two parameters N and K, single linear reseroir has one parameter $K_I$ and two-parallel linear reservoirs have two parameters $K_1,\;K_2$; where N denote the number of reservoirs and K is the storage coefficient of each reservoirs.

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The Monoid of Linear Hypersubstitutions

  • Changphas, Thawhat;Pibaljommee, Bundit;Denecke, Klaus
    • Kyungpook Mathematical Journal
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    • v.59 no.4
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    • pp.617-629
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    • 2019
  • A term is called linear if each variable which occurs in the term, occurs only once. A hypersubstitution is said to be linear if it maps any operation symbol to a linear term of the same arity. Linear hypersubstitutions have some importance in Theoretical Computer Science since they preserve recognizability [7]. We show that the collection of all linear hypersubstitutions forms a monoid. Linear hypersubstitutions are used to define linear hyperidentities. The set of all linear term operations of a given algebra forms with respect to certain superposition operations a function algebra. Hypersubstitutions define endomorphisms on this function algebra.

Comparison between Asynchronous and Synchronous Linear Motors as to Thermal Behavior

  • Eun, In-Ung
    • International Journal of Precision Engineering and Manufacturing
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    • v.2 no.3
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    • pp.61-68
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    • 2001
  • A linear motor has a lot of advantages in comparison with conventional feed mechanisms: high transitional speed, acceleration, high control performance and good positioning at high speed. Through the omission of a power transfer element, the linear motor shows no wear and no backlash, has along lifetime and is easy to assemble. Recently, the two types of linear motors, asynchronous and synchronous linear motors, are often applied to machine tools as a fast feed mechanism. In this paper, a comparison between the two types of linear motors as to power loss and thermal behavior is made. The heat sources of the linear motor-the electrical power loss in the motor and the frictional heat on the linear guidance-are measured and compared. Also, the temperature on the linear motor and machine structure is measured and presented.

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Structural Optimization of Truss with Non-Linear Response Using Equivalent Linear Loads (선형등가하중을 이용한 비선형 거동을 하는 트러스 구조물의 최적설계)

  • Park, Ki-Jong;Park, Gyung-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.4
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    • pp.467-474
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    • 2004
  • A numerical method and algorithms is proposed to perform optimization of non-linear response structures. An analytical and numerical method based finite element method is also proposed for the transformation of non-linear response into linear response. Loads transformed from this method are defined as the equivalent linear loads. With the loads and the transformed response, linear static optimization is performed for nonlinear response structure with geometric and/or material non-linearity. The results of the optimization are compared with them of typical non-linear response optimization using finite difference method. The proposed method is very efficient and derives good solution.

Dynamic Response of Linear Actuator with the Thrust Force of Transverse Flux Linear Motor (횡자속 선형전동기의 추력특성에 따른 선형액추에이터의 동특성)

  • Woo Byung-Chul;Kang Do-Hyun;Hong Do-Kwan
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.55 no.1
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    • pp.16-20
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    • 2006
  • The proposed paper presents an integrated linear actuator which combines Transverse Flux Linear Motor(TFLM) for Household elelctric applications. They both use the same primary magnetic circuit, but they have different secondary movers. The paper presents a new design of linear motor for a new electromagnetic linear actuator, an tintegrated TFLM. The calculated tthrust force is good agreement with experiments. We have studied a transient response of a linear actuator with a damping ratio, spring constant and specially a pressed power patterns for a constant stroke control.

Linear versus Non-linear Interference Cancellation

  • Buehrer, R.Michael;Nicoloso, Steven P.;Gollamudi, Sridhar
    • Journal of Communications and Networks
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    • v.1 no.2
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    • pp.118-133
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    • 1999
  • In this paper we compare linear and non-linear inter-ference cancellation for systems employing code division multi-ple access (CDMA) techniques. Specifically, we examine linear and non-linear parallel interference cancellation(also called multi-stage cancellation) in relationship to other multiuser detection al-gorithms. We show the explicit relationship between parallel inter-ference cancellation and the decorrelator (or direct matrix inver-sion). This comparison gives insight into the performance of paral-lel interference cancellation (PIC) and leads to vetter approaches. We also show that non-linear PIC approaches with explicit chan-nel setimation can provide performance improvement over linear PIC, especially when using soft non-linear symbol estimates. The application of interference cancellation to non-linear modulation techniques is also presented along with a discussion on minimum mean-squared error(MMSE) symbol estimation techniques. These are shown to further improve the performance of parallel cancella-tion.

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선형 저수지 유형의 parameter 연구

  • 서영재;고재웅
    • Proceedings of the Korea Water Resources Association Conference
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    • pp.151-158
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    • 1987
  • The purpose of thes study is to estimate the parameters of linear reservoir models in order to derive the instantaneous unit hydrograph from a given small experimental watershed. The linear reservoir model is a conceptual model, consisting of cascade or parallel equal linear reservoirs, preceded by a linear channel which involved NASH, SLR(single linear reservoir)and 2-PLR(two-parallel linear reservoir)model. The NASH model have two parameters N and K, single linear reservoir has one parameter K1 and two-parallel linear reservoirs have two parameters K1, K2;where N denote the number of reservoirs and K is the storage coefficient of each reservoirs.

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Piecewise Continuous Linear Density Estimator

  • Jang, Dae-Heung
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.4
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    • pp.959-968
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    • 2005
  • The piecewise linear histogram can be used as a simple and efficient tool for the density estimator. But, this piecewise linear histogram is discontinuous function. We suppose the piecewise continuous linear histogram as a simple and efficient tool for the density estimator and the alternative of the piecewise linear histogram.

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