• Title/Summary/Keyword: direct transformation

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A study on the treatment of a max-value cost function in parametric optimization (매개변수 종속 최적화에서 최대치형 목적함수 처리에 관한 연구)

  • Kim, Min-Soo;Choi, Dong-Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.10
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    • pp.1561-1570
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    • 1997
  • This study explores the treatment of the max-value cost function over a parameter interval in parametric optimization. To avoid the computational burden of the transformation treatment using an artificial variable, a direct treatment of the original max-value cost function is proposed. It is theoretically shown that the transformation treatment results in demanding an additional equality constraint of dual variables as a part of the Kuhn-Tucker necessary conditions. Also, it is demonstrated that the usability and feasibility conditions on the search direction of the transformation treatment retard convergence rate. To investigate numerical performances of both treatments, typical optimization algorithms in ADS are employed to solve a min-max steady-state response optimization. All the algorithm tested reveal that the suggested direct treatment is more efficient and stable than the transformation treatment. Also, the better performing of the direct treatment over the transformation treatment is clearly shown by constrasting the convergence paths in the design space of the sample problem. Six min-max transient response optimization problems are also solved by using both treatments, and the comparisons of the results confirm that the performances of the direct treatment is better than those of the tranformation treatment.

The Evaluations of Sensor Models for Push-broom Satellite Sensor

  • Lee, Suk-Kun;Chang, Hoon
    • Korean Journal of Geomatics
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    • v.4 no.1
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    • pp.31-37
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    • 2004
  • The aim of this research is comparing the existing approximation models (e.g. Affine Transformation and Direct Linear Transformation) with Rational Function Model as a substitute of rigorous sensor model of linear array scanner, especially push-broom sensor. To do so, this research investigates the mathematical model of each approximation method. This is followed by the assessments of accuracy of transformation from object space to image space by using simulated data generated by collinearity equations which incorporate or depict the physical aspects of linear array sensor.

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Response Analysis of 3-dimensional Floating Structure Using Beam Transformation (보 변환 기법을 이용한 3차원 부유체의 응답해석)

  • Kim, Byoung-Wan;Hong, Sa-Young;Kyoung, Jo-Hyun;Cho, Seok-Kyu
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.809-814
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    • 2006
  • In this paper, the modified direct method employing beam transformation technique is proposed in order to efficiently calculate hydroelastic responses of floating structure. Since the proposed method expresses the displacements of three-dimensional structure with those of transformed beam which leads to small number of equations of motion, the method is numerically efficient compared to the conventional direct method. To verify the efficiency of the proposed method a 500 m-long floating structure under wave loads is considered in numerical example. Displacements, bending moments, torsion moments and shear forces are calculated and computing tine is examined. The results are also compared with those of the conventional direct method.

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Response Analysis of 3-dimensional Floating Structure Using Beam Transformation (보 변환 기법을 이용한 3차원 부유체의 응답해석)

  • Hong, Sa-Young;Kyoung, Jo-Hyun;Cho, Seok-Kyu;Kim, Byoung-Wan
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.1 s.118
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    • pp.17-23
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    • 2007
  • In this paper, the modified direct method employing beam transformation technique is proposed in order to efficiently calculate hydroelastic responses of floating structure. Since the proposed method expresses the displacements of three-dimensional structure with those of transformed beam which leads to small number of equations of motion, the method is numerically efficient compared to the conventional direct method. To verify the efficiency of the proposed method, a 500 m-long floating structure under wave loads is considered in numerical example. Displacements, bending moments, torsion moments and shear forces are calculated and computing time is examined. The results are also compared with those of the conventional direct method.

A New fault Location Algorithm for a Line to Ground fault Using Direct 3-phase Circuit Analysis in Distribution Power Networks (3상회로 직접해석에 의한 배편계통 1선지락사고 고장거리 계산 알고리즘)

  • Choe, Myeon-Song;Lee, Seung-Jae;Lee, Deok-Su;Jin, Bo-Geon;Min, Byeong-Un
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.51 no.8
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    • pp.409-416
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    • 2002
  • This paper presents a fault location algorithm using direct 3-phase circuit analysis for distribution power networks. The unbalanced feature of distribution networks due to single phase loads or asymmetric operation prohibits us from using the conventional symmetrical component transformation. Even though the symmetrical component transformation provides us with a very easy tool in three phase network analysis, it is limited to balanced systems in utilizing its strong point, which is not suitable for distribution networks. In this paper, a fault location algorithm using direct 3-phase circuit analysis is developed. The algorithm is derived and it Is shown that the proposed method if we use matrix inverse lemma, is not more difficult then the conventional methods using symmetrical component transformation. Since the symmetrical component transformation is not used in the suggested method, unbalanced networks also can be handled with the same difficulty as balanced networks. The case study results show the correctness and effectiveness of the proposed algorithm.

The Partial Transformation of Clothing Construction in Modern Fashion (현대 패션에 나타난 의복구성의 부분 변형)

  • Kim, Young-Ran
    • Journal of the Korea Fashion and Costume Design Association
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    • v.9 no.1
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    • pp.103-122
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    • 2007
  • Fashion have been expressed by a face through various a period, social change, and various culture changing. Human expresses as "Transformation" by applying these needs of changing to the fashion. A origin tribe expressed its own self by using direct body transformation and extreme decorations in the past. However, human express creative and esthetic desire based on shape, material, and transformation method in the present time characteristics of the body. Exceptional transformation breaking a existing fixed idea appeared frequently due to dissolution through transformation which is positive expression method in the fashion from 20th century. As a results, followings are obtained in this study. First, human body transforms by using a tool or intermediation in investigation of aesthetic meaning for human body. The object, Transformation, is stably transformed by disintegration, distortion, exaggeration and simplification reduction, as design's sensitivity. Second, transformation from relation of clothing composition is expressed by extension, reduction, simplification, and dissolution. In transformation from original tribe's sensitivity, past decorative desire lead to transformation of human body. To give variable change from past to present fashion, external formative will is introduced. Then, extreme expression is made by direct transformation of clothing type. It seems to be accomplished that human body's expression method is continuously changed into extension, exaggeration, reduction, and dissolution from transformation method as described before. Transformation of modem fashion is expression method by creative supervision. Extreme transformation substituted body's each part is based on immanent play and representative satisfaction. Through these transformation, it is judged that variety of creative type is achieved.

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Tomographic reconstruction of Asymmetric Spray by Direct Sampling Method (직접샘플링에 의한 비대칭 분무의 토모그래피 재구성)

  • Lee, C.H.;Won, J.C.
    • Journal of ILASS-Korea
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    • v.7 no.4
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    • pp.9-15
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    • 2002
  • Convolution Fourier transformation tomographically reconstructs the spatially resolved spray injection rate from direct measuring cells. Asymmetric sprays generated from a twin-hole air shroud injector are tested with 12 equiangular projections of measurements. For each projection angle, line of sight integrated injection rate was measured at 35 positions with equal spacing measuring cells of 3 mm in width, 100 mm in length, 55 mm in depth and 0.5 mm thickness of separating wall. Interpolated data between the projection angles effectively increase the number of projections, which significantly enhances the signal-to-noise level in the reconstructed data. This modified convolution Fourier transformation scheme predicts well the structure of asymmetric sprays. Comparative study has been made between sprays with and without air shrouding. Tomograhpic reconstruction of injection rate from direct measuring cells obtained can be used to estimate the accuracy of volume fraction of spray from the LDPA tomographic reconstruction.

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Transcoding Algorithm for SMV and G.723.1 Vocoders via Direct Parameter Transformation (SMV와 G.723.1 음성부호화기를 위한 파라미터 직접 변환 방식의 상호부호화 알고리듬)

  • 서성호;장달원;이선일;유창동
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.6
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    • pp.61-70
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    • 2003
  • In this paper, a transcoding algorithm for the Selectable Mode Vocoder (SMV) and the G.723.1 speech coder via direct parameter transformation is proposed. In contrast to the conventional tandem transcoding algorithm, the proposed algorithm converts the parameters of one coder to the other without going through the decoding and encoding process. The proposed algorithm is composed of four parts: the parameter decoding, line spectral pair (LSP) conversion, pitch period conversion, excitation conversion and rate selection. The evaluation results show that the proposed algorithm achieves equivalent speech quality to that of tandem transcoding with reduced computational complexity and delay.

A Study on the Three Dimensional Coordinates Analysis by Direct Linear Transformation (직접선형변환을 이용한 3차원 좌표해석에 관한 연구)

  • 김감래;이호남
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.5 no.2
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    • pp.47-55
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    • 1987
  • In this paper, the direct linear transformation is described in which a inner and exterior orientation parameters are treated as unknown for non-iterative direct space resection, and the computer program was developed to obtain object space coordinates. Image coordinates measurements are conducted with analogue stereo-plotter and digitizer. To prove the appropriateness of the two image coordinate measurement devices and the DLT method, the standard errors of object space coordinates are compared with semi-analytical method.

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