• Title/Summary/Keyword: daub

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Commentary on Soft Ground TBM Tunnel Face Support Calculation Methods (연약지반 TBM 터널 막장지보 계산방법 해설)

  • Jee, Warren Wangryul;Yoo, Jung Hyun
    • Tunnel and Underground Space
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    • v.28 no.2
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    • pp.186-192
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    • 2018
  • The German Tunnelling Committee (DAUB) recently published new recommendations for face support calculations; Zdenek Zizka and Markus Thewes of Ruhr University Bochum actively discuss and explain these new recommendations where these recommendations are intended to assist in choosing between various calculation methods which are also dependent on ground conditions. The guidelines also discuss important scientific approaches with face stability calculations, mainly those due to earth pressure and groundwater pressure on the tunnel face. This paper aims to explain these recommendations through Zdenek Zizak and Markus Thewes's discussion on these Tunnel Face Support Calculation Methods.

The Protective Relaying Scheme of Power Transformer Using Wavelet Based Neural Networks (웨이브렛 변환을 바탕으로 한 신경회로망을 이용한 전력용 변압기 보호 계전기법)

  • Gwon, Gi-Baek;Seo, Hui-Seok;Yun, Seok-Mu;Sin, Myeong-Cheol
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.51 no.3
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    • pp.134-142
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    • 2002
  • This paper presents a new method for the protective relaying scheme in power transformer using wavelet based neural networks. This approach is as fellows. After approximation and detail information is extracted by daub wavelet transform from differential current of power transformer, the former is used for obtaining the rate of differential currents and restrain currents, the latter used as the input of artificial neural networks to avoid the Hiss-operation in over-exciting state and magnetizing inrush state of power transformer. The simulation of EMTP with respect to different faults, inrush conditions and over-exciting conditions in power transformer have been conducted, and the results preyed that the proposed method is able to discriminate magnetizing inrush states, over-exciting stales and internal faults.

A Study on Factors Affecting Changes in Estimating Standards in Plaster Work (미장공사의 품기준 변화 요인에 관한 연구)

  • Oh, Jae-Hoon;An, Bang-Yul
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.232-233
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    • 2019
  • The plater work in the standard of estimate presents a variety of construction types. However, there is a part that does not fit the change of specification standards and on-site construction status, and it was revised in 2019's standard of estimate. In this study, we analyzed in detail the factors affecting the changes in estimating standards in the plater work. There were changes in the specification standards previously presented as primary coat, secondary coat, and formal coat as well as changes in on-site construction status such as thickness according to the number of plastering. Therefore, it is analyzed that the estimating standards can be classified by the number of finishes according to the site conditions by reflecting the analysis of the specification standards and site application status, and suggesting the finishing standards according to the number of plastering.

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A study on optimal Image Data Multiresolution Representation and Compression Through Wavelet Transform (Wavelet 변환을 이용한 최적 영상 데이터 다해상도 표현 및 압축에 관한 연구)

  • Kang, Gyung-Mo;Jeoung, Ki-Sam;Lee, Myoung-Ho
    • Proceedings of the KOSOMBE Conference
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    • v.1994 no.12
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    • pp.31-38
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    • 1994
  • This paper proposed signal decomposition and multiresolution representation through wavelet transform using wavelet orthonormal basis. And it suggested most appropriate filter for scaling function in multiresoltion representation and compared two compression method, arithmetic coding and Huffman coding. Results are as follows 1. Daub18 coefficient is most appropriate in computing time, energy compaction, image quality. 2. In case of image browsing that should be small in size and good for recognition, it is reasonable to decompose to 3 scale using pyramidal algorithm. 3. For the case of progressive transmittion where requires most grateful image reconstruction from least number of sampls or reconstruction at any target rate, I embedded the data in order of significance after scaling to 5 step. 4. Medical images such as information loss is fatal have to be compressed by lossless method. As a result from compressing 5 scaled data through arithmetic coding and Huffman coding, I obtained that arithmetic coding is better than huffman coding in processing time and compression ratio. And in case of arithmetic coding I could compress to 38% to original image data.

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