• Title/Summary/Keyword: Basis

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ON PAIRWISE GAUSSIAN BASES AND LLL ALGORITHM FOR THREE DIMENSIONAL LATTICES

  • Kim, Kitae;Lee, Hyang-Sook;Lim, Seongan;Park, Jeongeun;Yie, Ikkwon
    • Journal of the Korean Mathematical Society
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    • v.59 no.6
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    • pp.1047-1065
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    • 2022
  • For two dimensional lattices, a Gaussian basis achieves all two successive minima. For dimension larger than two, constructing a pairwise Gaussian basis is useful to compute short vectors of the lattice. For three dimensional lattices, Semaev showed that one can convert a pairwise Gaussian basis to a basis achieving all three successive minima by one simple reduction. A pairwise Gaussian basis can be obtained from a given basis by executing Gauss algorithm for each pair of basis vectors repeatedly until it returns a pairwise Gaussian basis. In this article, we prove a necessary and sufficient condition for a pairwise Gaussian basis to achieve the first k successive minima for three dimensional lattices for each k ∈ {1, 2, 3} by modifying Semaev's condition. Our condition directly checks whether a pairwise Gaussian basis contains the first k shortest independent vectors for three dimensional lattices. LLL is the most basic lattice basis reduction algorithm and we study how to use LLL to compute a pairwise Gaussian basis. For δ ≥ 0.9, we prove that LLL(δ) with an additional simple reduction turns any basis for a three dimensional lattice into a pairwise SV-reduced basis. By using this, we convert an LLL reduced basis to a pairwise Gaussian basis in a few simple reductions. Our result suggests that the LLL algorithm is quite effective to compute a basis with all three successive minima for three dimensional lattices.

An Efficient Algorithm for Computing Multiplicative Inverses in GF($2^m$) Using Optimal Normal Bases (최적 정규기저를 이용한 효율적인 역수연산 알고리즘에 관한 연구)

  • 윤석웅;유형선
    • The Journal of Society for e-Business Studies
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    • v.8 no.1
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    • pp.113-119
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    • 2003
  • This paper proposes a new multiplicative inverse algorithm for the Galois field GF (2/sup m/) whose elements are represented by optimal normal basis type Ⅱ. One advantage of the normal basis is that the squaring of an element is computed by a cyclic shift of the binary representation. A normal basis element is always possible to rewrite canonical basis form. The proposed algorithm combines normal basis and canonical basis. The new algorithm is more suitable for implementation than conventional algorithm.

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A study on the necessity for using the method of cash basis accounting on taxation. (세법상 현금주의 도입의 필요성에 관한 연구)

  • Choi, Won
    • Journal of Industrial Convergence
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    • v.1 no.2
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    • pp.173-191
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    • 2003
  • Usually there are two ways in the method of accounting on tax purpose. One is the method of accrual basis accounting, the other is the method of cash basis accounting. Accrual basis accounting is used broadly not only in financial purpose, but also tax purpose. But, that method is not fit at some special case. For example, lawyer, bank, consulting, small business would like to use the method of cash basis accounting because it is more convenient in book-keeping than the method of accrual basis. I insist on regulating this cash basis accounting.

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MP2 Basis Set Limit Binding Energy Estimates of Hydrogen-bonded Complexes from Extrapolation-oriented Basis Sets

  • Park, Young-Choon;Lee, Jae-Shin
    • Bulletin of the Korean Chemical Society
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    • v.28 no.3
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    • pp.386-390
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    • 2007
  • By use of a simple two-point extrapolation scheme estimating the correlation energies of the molecules along with the basis sets specifically targeted for extrapolation, we have shown that the MP2 basis set limit binding energies of large hydrogen-bonded complexes can be accurately predicted with relatively small amount of computational cost. The basis sets employed for computation and extrapolation consist of the smallest correlation consistent basis set cc-pVDZ and another basis set made of the cc-pVDZ set plus highest angular momentum polarization functions from the cc-pVTZ set, both of which were then augmented by diffuse functions centered on the heavy atoms except hydrogen in the complex. The correlation energy extrapolation formula takes the (X+1)-3 form with X corresponding to 2.0 for the cc-pVDZ set and 2.3 for the other basis set. The estimated MP2 basis set limit binding energies for water hexamer, hydrogen fluoride pentamer, alaninewater, phenol-water, and guanine-cytosine base pair complexes of nucleic acid by this method are 45.2(45.9), 36.1(37.5), 10.9(10.7), 7.1(6.9), and 27.6(27.7) kcal/mol, respectively, with the values in parentheses representing the reference basis set limit values. A comparison with the DFT results by B3LYP method clearly manifests the effectiveness and accuracy of this method in the study of large hydrogen-bonded complexes.

A Comparative Study on the Traditional Depreciation Method and Depreciation on Current Cost Basis Method (전통적(傳統的) 감가상각방법(減價償却方法)과 시가상각방법(時價償却方法)에 대한 비판적(批判的) 연구(硏究) - Inflation 시(時)를 중심(中心)으로 -)

  • Park, Kyung-Rak
    • Korean Business Review
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    • v.3
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    • pp.183-210
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    • 1990
  • In this study traditional depreciation method has been analysed carefully and then compared with the depreciation on current cost basis for the purpose of reviewing the basic theory underlying depreciation on current cost basis in view of the current situation demanding new method of depreciation. In this treatise the inevitability of rejecting the basic theory of depreciation and traditional depreciation method has been treated. Furthermore the probable consequence when such refutation of traditional depreciation occurs is studied. How to resolve such problems and what is the basis for claiming for depreciation on current cost basis have been also analysed. Through this analysis and research the following conclusions have been drawn: 1. For the purpose of complete recovery of invested capital depreciation on current cost basis is demanded. 2. For the purpose of undertaking realistic profit computation and accounting to apply to comparison and analysis of business operation depreciation on current cost basis is required. 3. When the feasibility of depreciation on current cost basis is guaranteed' then depreciation on current cost basis can be promoted. 4. Depreciation on current cost basis should be studied from the standpoint of evaluation position.

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Selecting Optimal Basis Function with Energy Parameter in Image Classification Based on Wavelet Coefficients

  • Yoo, Hee-Young;Lee, Ki-Won;Jin, Hong-Sung;Kwon, Byung-Doo
    • Korean Journal of Remote Sensing
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    • v.24 no.5
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    • pp.437-444
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    • 2008
  • Land-use or land-cover classification of satellite images is one of the important tasks in remote sensing application and many researchers have tried to enhance classification accuracy. Previous studies have shown that the classification technique based on wavelet transform is more effective than traditional techniques based on original pixel values, especially in complicated imagery. Various basis functions such as Haar, daubechies, coiflets and symlets are mainly used in 20 image processing based on wavelet transform. Selecting adequate wavelet is very important because different results could be obtained according to the type of basis function in classification. However, it is not easy to choose the basis function which is effective to improve classification accuracy. In this study, we first computed the wavelet coefficients of satellite image using ten different basis functions, and then classified images. After evaluating classification results, we tried to ascertain which basis function is the most effective for image classification. We also tried to see if the optimum basis function is decided by energy parameter before classifying the image using all basis functions. The energy parameters of wavelet detail bands and overall accuracy are clearly correlated. The decision of optimum basis function using energy parameter in the wavelet based image classification is expected to be helpful for saving time and improving classification accuracy effectively.

Basis Translation Matrix between Two Isomorphic Extension Fields via Optimal Normal Basis

  • Nogami, Yasuyuki;Namba, Ryo;Morikawa, Yoshitaka
    • ETRI Journal
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    • v.30 no.2
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    • pp.326-334
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    • 2008
  • This paper proposes a method for generating a basis translation matrix between isomorphic extension fields. To generate a basis translation matrix, we need the equality correspondence of a basis between the isomorphic extension fields. Consider an extension field $F_{p^m}$ where p is characteristic. As a brute force method, when $p^m$ is small, we can check the equality correspondence by using the minimal polynomial of a basis element; however, when $p^m$ is large, it becomes too difficult. The proposed methods are based on the fact that Type I and Type II optimal normal bases (ONBs) can be easily identified in each isomorphic extension field. The proposed methods efficiently use Type I and Type II ONBs and can generate a pair of basis translation matrices within 15 ms on Pentium 4 (3.6 GHz) when $mlog_2p$ = 160.

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내부해로부터 최적기저 추출에 관한 연구

  • 박찬규;박순달
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1996.04a
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    • pp.24-29
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    • 1996
  • If the LP problem doesn't have the optimal soultion uniquely, the solution fo the primal-dual barrier method converges to the interior point of the optimal face. Therefore, when the optimal vertex solution or the optimal basis is required, we have to perform the additional procedure to recover the optimal basis from the final solution of the interior point method. In this paper the exisiting methods for recovering the optimal basis or identifying the optimal solutions are analyzed and the new methods are suggested. This paper treats the two optimal basis recovery methods. One uses the purification scheme and the simplex method, the other uses the optimal face solutions. In the method using the purification procedure and the simplex method, the basic feasible solution is obtained from the given interior solution and then simplex method is performed for recovering the optimal basis. In the method using the optimal face solutions, the optimal basis in the primal-dual barrier method is constructed by intergrating the optimal solution identification technique and the optimal basis extracting method from the primal-optimal soltion and the dual-optimal solution.

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Radial basis function network design for chaotic time series prediction (혼돈 시계열의 예측을 위한 Radial Basis 함수 회로망 설계)

  • 신창용;김택수;최윤호;박상희
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.4
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    • pp.602-611
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    • 1996
  • In this paper, radial basis function networks with two hidden layers, which employ the K-means clustering method and the hierarchical training, are proposed for improving the short-term predictability of chaotic time series. Furthermore the recursive training method of radial basis function network using the recursive modified Gram-Schmidt algorithm is proposed for the purpose. In addition, the radial basis function networks trained by the proposed training methods are compared with the X.D. He A Lapedes's model and the radial basis function network by nonrecursive training method. Through this comparison, an improved radial basis function network for predicting chaotic time series is presented. (author). 17 refs., 8 figs., 3 tabs.

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