• Title/Summary/Keyword: nested design

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HTS Nested magnet wound with 12 mm GdBCO tape and 4.4 mm YBCO tape

  • Kang, Myunghun;Ku, Myunghwan;Cha, Gueesoo;Lim, Hyoungwoo
    • Progress in Superconductivity and Cryogenics
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    • v.17 no.2
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    • pp.50-53
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    • 2015
  • The properties of High Temperature Superconducting (HTS) tapes are progressing, as HTS tapes evolve from 1st generation to 2nd generation. This paper presents design and construction of a 2nd generation HTS magnet consisting of two nested GdBCO and YBCO pancake coils. Two HTS tapes of different widths were used to wind the HTS nested magnet. Considering that a higher magnetic field is applied to the inner magnet than to the outer magnet, 12 mm GdBCO tape was used for winding the inner magnet, which consisted of four single pancake windings. Eight double pancake windings wound with 4.4 mm YBCO tapes were used for the outer magnet. The test results show that the central magnetic field of the HTS nested magnet was 920 mT. The measured critical currents of the inner and outer magnet at 77K were 80.8 A and 32.6 A, respectively.

Variance components for two-way nested design data

  • Choi, Jaesung
    • Communications for Statistical Applications and Methods
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    • v.25 no.3
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    • pp.275-282
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    • 2018
  • This paper discusses the use of projections for the sums of squares in the analyses of variance for two-way nested design data. The model for this data is assumed to only have random effects. Two different sizes of experimental units are required for a given experimental situation, since nesting is assumed to occur both in the treatment structure and in the design structure. So, variance components are coming from the sources of random effects of treatment factors and error terms in different sizes of experimental units. The model for this type of experimental situation is a random effects model with more than one error terms and therefore estimation of variance components are concerned. A projection method is used for the calculation of sums of squares due to random components. Squared distances of projections instead of using the usual reductions in sums of squares that show how to use projections to estimate the variance components associated with the random components in the assumed model. Expectations of quadratic forms are obtained by the Hartley's synthesis as a means of calculation.

A Design Guide of 3-stage CMOS Operational Amplifier with Nested Gm-C Frequency Compensation

  • Lee, Jae-Seung;Bae, Jun-Hyun;Kim, Ho-Young;Um, Ji-Yong;Sim, Jae-Yoon;Park, Hong-June
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.7 no.1
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    • pp.20-27
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    • 2007
  • An analytic design guide was formulated for the design of 3-stage CMOS OP amp with the nested Gm-C(NGCC) frequency compensation. The proposed design guide generates straight-forwardly the design parameters such as the W/L ratio and current of each transistor from the given design specifications, such as, gain-bandwidth, phase margin, the ratio of compensation capacitance to load capacitance. The applications of this design guide to the two cases of 10pF and 100pF load capacitances, shows that the designed OP amp work with a reasonable performance in both cases, for the range of compensation capacitance from 10% to 100% of load capacitance.

Derivation of Expected Mean Squares (EMS) Using Venn Diagram by the Type of Experimental Design (실험설계 유형별 Venn Diagram을 이용한 EMS 도출)

  • Choi, Sung-Woon
    • Proceedings of the Safety Management and Science Conference
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    • 2011.04a
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    • pp.695-699
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    • 2011
  • The study presents an efficient design method of Venn Diagram that can be used when implementing the quality design of experiments based on generalizability theory. The paper examines four mixed and combined models that are designed by fixed factor, random factor, crossed factor and nested factor. The models considered in this research are $A^*{\times}B^*{\times}C$, (B: $A^*$)${\times}C$, $A{\times}B{\times}C$ and (B: A)${\times}C$.

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Logistic regression model for major separation rate

  • Choi, Jae-Sung
    • Journal of the Korean Data and Information Science Society
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    • v.13 no.2
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    • pp.129-138
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    • 2002
  • This paper deals with logistic regression models for analysing separation rates from majors. The model building procedure shows how to incoporate the effects of some factors causing from three-way nested sampling scheme and discusses what type of characteristics as independent variables directly affecting the rates should be considered.

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A cumulative logit mixed model for ordered response data

  • Choi, Jae-Sung
    • 한국데이터정보과학회:학술대회논문집
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    • 2004.04a
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    • pp.121-126
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    • 2004
  • This paper discusses about how to build up a mixed-effects model using cumulative logits when there are some factors are fixed and others are random. Random factors are assumed to be coming from a two-way nested design for choosing individuals or experimental units to apply treatments. Estimation procedure for the unknown parameters in a suggested model is also discussed by an illustrated example.

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Design of Gain-Scheduled Controllers for Linear Systems with Input Constraints (제한된 입력 특성을 갖는 선형 시스템의 이득 계획 제어기 설계)

  • Song, Yong-Hui;Kim, Jin-Hun
    • Proceedings of the KIEE Conference
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    • 2003.11b
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    • pp.335-338
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    • 2003
  • In this paper, we considered the design of gain scheduled controllers for linear systems with input constraints. The gain scheduled control is a method that uses larger control gain when the states are smaller, and smaller gain when it is larger. By doing this, we can use a full actuator capacity. Also we allow the over-saturation in control to improve the performance. First, we derive a control and a reachable set expressed as LMI form, while minimizing the $L_2$ gain from the disturbance to the measured output. Next, the reachable set is divided as nested subsets, and the control gains are obtained by minimizing the $L_2$ gain at each nested subset. Finally, the control gains are scheduled according to the status of states, i.e., the nested-subset in which the states are located. Performance of the proposed technique is illustrated through simulations of a six-story building subject to earthquake ground motion.

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A Mixed Model for Nested Structural Repeated Data (지분구조의 반복측정 자료에 대한 혼합모형)

  • Choi, Jae-Sung
    • The Korean Journal of Applied Statistics
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    • v.22 no.1
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    • pp.181-188
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    • 2009
  • This paper discusses the covariance structures of data collected from an experiment with a nested design structure, where a smaller experimental unit is nested within a larger one. Due to the nonrandomization of repeated measures factors to the nested experimental units, compound symmetry covariance structure is assumed for the analysis of data. Treatments are given as the combinations of the levels of random factors and fixed factors. So, a mixed-effects model is suggested under compound symmetry structure. An example is presented to illustrate the nesting in the experimental units and to show how to get the parameter estimates in the fitted model.

An Optimal Design Method for the Multidimensional Nested Attribute Indexes (다차원 중포 속성 색인구조의 최적 설계기법)

  • 이종학
    • Journal of Korea Multimedia Society
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    • v.6 no.2
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    • pp.194-207
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    • 2003
  • This paper presents an optimal design methodology for the multidimensional nested attribute index (MD-NAI) that uses a multidimensional index structure for indexing the nested attributes in object databases. The MD-NAI efficiently supports complex queries involving both nested attributes and class hierarchies, which are not supported by the nested attribute index using one-dimensional index structure such as $B^+$-tree. However, the performance of the MD-NAI is very degraded in some cases of user's query types. In this paper, for the performance enhancement of the MD-NAI, we first determine the optimal shape of index page region by using the query information about the nested predicates, and then construct an optimal MD NAI by applying a region splitting strategy that makes the shape of the page regions of the MD-NAI as close as possible to the predetermined optimal one. For performance evaluation, we perform extensive experiments with the MD-NAI using various types of nested predicates and object distribution. The results indicate that our proposed method builds optimal MD-NAI regardless of the query types and object distributions. When the interval ratio of a three-dimensional query region is 1:16:236, the performance of the proposed method is enhanced by as much as 5.5 times over that of the conventional method employing the cyclic splitting strategy.

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Bearing Estimate Error Correction Method for a Nested Array (네스티드 배열의 방위각 추정오차 보정기법)

  • 이장식;이정훈;이수형;이균경
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.5
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    • pp.110-115
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    • 2001
  • In this paper, we propose a beamformer adequate for the nested away that is generally used for multiple frequency band signal processing. The nonisotropic beam pattern of channel in this array causes two problems: the bearing-estimate error of mainlobe and the difference between design and output in sidelobe level. By separating the time delay among channel signals and the time delay among sensor signals in channel, we can remove the effects of the nonisotropic beam pattern of channel in the beamformer output. Through this process, a method to correct simultaneously these problems is proposed.

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