• Title/Summary/Keyword: DMI (Direct matrix input)

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Topology Optimization of a Lightweight Multi-material Cowl Cross Member Using Matrix Input with the Craig Bampton Nodal Method

  • Son, Dong il;So, Sangwoo;Choi, Dong hyuk;Kim, Daeil
    • Composites Research
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    • v.32 no.5
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    • pp.243-248
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    • 2019
  • As demand of light weight in the automotive industry has increased, the cowl cross member has been investigated using various methods to change the material. Conventionally, a cowl cross member has been made of steel and aluminum, but recently researchers tested multi-material such as aluminum and plastic. We studied a new model of the cowl cross member made of composite and non ferrous materials. For products with a high degree of freedom in design, generally, the method of topology optimization is advantageous and for the partial bracket part of the cowl cross member had a degree of freedom in the design, a topology optimization is appropriate. Considering the characteristics of the cowl cross members, we need research to minimize the weight while having the performance of noise, vibration and harshness(NVH). Taking the mounting status of the product into consideration, we used an assembly model to optimize the cowl cross member. But this method took too much time so we considered simple cowl cross member assemble conditions using the direct matrix input method(DMI) with the Craig-Bampton Nodal Method. This method is capable of considering the status of the assembly without assembling the model, which reduced the solving time and increased the accuracy comparison with a cowl cross member without DMI.

A Study on Performance Improvement of Adaptive SLC System using Eigenanalysis Method (Eigenanalysis 방식을 이용한 적응 SLC(sidelobe canceller)시스템의 성능향상에 관한 연구)

  • 김세연;정신철;이병섭
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.5
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    • pp.694-704
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    • 2001
  • In this work, We evaluate the performance of eigencanceller which can suppress directional interferences and noise effectively while maintaining specified beam pattern constraints. The constraints and optimal weight vector of eigencanceller vary by using interference and noise or desired signal, interference and noise as array input signal. From the analysis results in the steady state, We show that weight vectors in each case are simplified the form of projection equation that belongs to desired subspace orthogonal to interference subspace and eigencanceller has the better performance than DMI method through mathematical analysis and simulation.

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