• 제목/요약/키워드: Tables

검색결과 1,864건 처리시간 0.034초

가변 시간 K차 뉴톤-랍손 부동소수점 나눗셈 (A Variable Latency K'th Order Newton-Raphson's Floating Point Number Divider)

  • 조경연
    • 대한임베디드공학회논문지
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    • 제9권5호
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    • pp.285-292
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    • 2014
  • The commonly used Newton-Raphson's floating-point number divider algorithm performs two multiplications in one iteration. In this paper, a tentative K'th Newton-Raphson's floating-point number divider algorithm which performs K times multiplications in one iteration is proposed. Since the number of multiplications performed by the proposed algorithm is dependent on the input values, the average number of multiplications per an operation in single precision and double precision divider is derived from many reciprocal tables with varying sizes. In addition, an error correction algorithm, which consists of one multiplication and a decision, to get exact result in divider is proposed. Since the proposed algorithm only performs the multiplications until the error gets smaller than a given value, it can be used to improve the performance of a floating point number divider unit. Also, it can be used to construct optimized approximate reciprocal tables.

Comparison of Efficiency for Different Switching Tables in Six-Phase Induction Motor DTC Drive

  • Taheri, Asghar;Rahmati, Abdolreza;Kaboli, Shahriyar
    • Journal of Power Electronics
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    • 제12권1호
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    • pp.128-135
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    • 2012
  • In this paper, different switching tables proposed for the Direct Torque Controlled (DTC) of a six-phase induction machine are simulated and implemented. A six-phase induction motor has 64 space voltage vectors which result in increased complexity in the selecting of inverters switching. The unsuitable selection of a switching table leads to large harmonics especially at low speed and it also reduces drive efficiency. A six-phase induction machine has large zero sequence harmonic currents of the order $6{\kappa}{\pm}1$. These harmonic currents are varied in various techniques. Decreasing this loss is essential in a six-phase induction machine. The main purpose of this paper is to improve the ST-DTC of six-phase induction machines to reduce the voltage and current harmonics and the torque pulsation. Selecting a suitable method for minimizing these harmonics is very important.

한국 의료 및 측정기기산업의 투자파급효과 분석 (An Analysis on the Economic Effects of the Medical and Measuring Instrument Industry)

  • 서정교
    • 보건의료산업학회지
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    • 제6권3호
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    • pp.219-229
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    • 2012
  • In these days, the interest on medical industry is increasing around the world. This paper attempts to estimate the economic effects of the medical and measuring instrument industry through the Input-Output Analysis. Especially, 78*78 Sector Tables were used as the first analysis tool. So then, 79*79 Sector Tables adjusted were used for that industry. The main analysis tools of this study are comparing and analyzing backward and forward linkage effect, the induced effect of the self industry and other industries and the induced coefficients such as products, value-added, employee's pay, sales surplus, employment. According to the result of analysis, the medical and measuring instrument industry has great economic impacts which affects the major macroeconomic factors such as production and backward linkage effect. And the induced effects of the self medical and measuring instrument industry are significant compared to other industries in aspects of production, employee's pay and sales surplus.

Large tests of independence in incomplete two-way contingency tables using fractional imputation

  • Kang, Shin-Soo;Larsen, Michael D.
    • Journal of the Korean Data and Information Science Society
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    • 제26권4호
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    • pp.971-984
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    • 2015
  • Imputation procedures fill-in missing values, thereby enabling complete data analyses. Fully efficient fractional imputation (FEFI) and multiple imputation (MI) create multiple versions of the missing observations, thereby reflecting uncertainty about their true values. Methods have been described for hypothesis testing with multiple imputation. Fractional imputation assigns weights to the observed data to compensate for missing values. The focus of this article is the development of tests of independence using FEFI for partially classified two-way contingency tables. Wald and deviance tests of independence under FEFI are proposed. Simulations are used to compare type I error rates and Power. The partially observed marginal information is useful for estimating the joint distribution of cell probabilities, but it is not useful for testing association. FEFI compares favorably to other methods in simulations.

분류표의 시대구분에 대한 연구 (A Study on the Chronological Division in Classification)

  • 정해성
    • 한국도서관정보학회지
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    • 제35권4호
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    • pp.469-489
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    • 2004
  • 시대구분(연대범주)은 주제와 결합하여 주제의 범위를 특정 연대(시대)로 한정하는 방법으로서 분류표에 따라서 사용기법을 달리 하고 있다. CC와 UDC는 공통구분표를 통해 일관성있고 분명한 시대구분이 가능하다. DDC와 KDC는 표준구분, 역사류, 문학류에 따라 시대구분 기호를 다르게 사용하고 있다.

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광학정반용 에폭시 접착제 개발을 위한 실험적 연구 (An Experimental Study for the Development of Epoxy Adhesives for Optical Top)

  • 길형균;윤석원;김광산
    • 한국소음진동공학회논문집
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    • 제20권8호
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    • pp.727-733
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    • 2010
  • Optical tables provide a platform for the establishment and test of measurement systems which use Laser. Therefore, not only static characteristics such as surface flatness, static stiffness and etc. but dynamic response characteristics is very important design parameter. The dynamic stiffness is generally estimated through the modal test, and compliance is used as a representative performance standard. Recently there is an example of defining the dynamic deflection coefficient and using it as a new performance standard of the dynamic stiffness, but it is not generalized yet in industry. In this study, we verify the validity of existing DDC calculus by making an experiment on granite. And for improvement in damping performance of optical tables, we are going to evaluate the effect of fillers on the compliance, then develop an epoxy adhesive based on the result of this experiment.

Uncertainty Analysis of Concrete Structures Using Modified Latin Hypercube Sampling Method

  • Yang, In-Hwan
    • International Journal of Concrete Structures and Materials
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    • 제18권2E호
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    • pp.89-95
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    • 2006
  • This paper proposes a modified method of Latin Hypercube sampling to reduce the variance of statistical parameters in uncertainty analysis of concrete structures. The proposed method is a modification of Latin Hypercube sampling method. This analysis method uses specifically modified tables of random permutations of ranked numbers. In addition, the Spearman coefficient is used to make modified tables. Numerical analysis is carried out to predict the uncertainty of axial shortening in prestressed concrete bridge. Statistical parameters obtained from modified Latin Hypercube sampling method and conventional Latin Hypercube sampling method are compared and evaluated by a numeric analysis. The results show that the proposed method results in a decrease in the variance of statistical parameters. This indicates the method is efficient and effective in the uncertainty analysis of complex structural system such as prestressed concrete bridges.