• 충청수학회지
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• 제26권4호
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• pp.743-748
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• 2013

The purpose of this note is to introduce interesting and useful properties differential-basis and p-basis in theorem 3.3. The result gives a existence differential basis of $S^P$ [$[{\Lambda}_1]$](S) which has a p-basis over $S^p$ ($S^p[{\Lambda}_1]$).

• ETRI Journal
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• 제30권2호
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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.

• Bulletin of the Korean Chemical Society
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• 제28권3호
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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.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제26권1호
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• pp.13-33
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• 2019

The main aim of this paper is to establish some comparative growth properties of composite entire functions on the basis of their relative (p, q)-th order, relative (p, q)-th lower order, relative (p, q)-th type, relative (p, q)-th weak type of entire function with respect to another entire function where p and q are any two positive integers.

• Imaging Science in Dentistry
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• 제48권1호
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• pp.41-44
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• 2018

Purpose: To evaluate the effect of different numbers of basis images and the use of metal artifact reduction (MAR) on the production and reduction of artifacts in cone-beam computed tomography images. Materials and Methods: An acrylic resin phantom with a metal alloy sample was scanned, with 450 or 720 basis images and with or without MAR. Standard deviation values for the test areas (around the metal object) were obtained as a way of measuring artifact production. Two-way analysis of variance was used with a 5% significance level. Results: There was no significant difference in artifact production among the images obtained with different numbers of basis images without MAR (P=.985). MAR significantly reduced artifact production in the test areas only in the protocol using 720 basis images (P=.017). The protocol using 450 basis images with MAR showed no significant difference in artifact production when compared to the protocol using 720 basis images with MAR (P=.579). Conclusion: Protocols with a smaller number of basis images and with MAR activated are preferable for minimizing artifact production in tomographic images without exposing the patient to a greater radiation dose.

• ETRI Journal
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• 제29권6호
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• pp.769-778
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• 2007

This paper proposes a multiplication algorithm for $F_{p^m}$, which can be efficiently applied to many pairs of characteristic p and extension degree m except for the case that 8p divides m(p-1). It uses a special class of type- Gauss period normal bases. This algorithm has several advantages: it is easily parallelized; Frobenius mapping is easily carried out since its basis is a normal basis; its calculation cost is clearly given; and it is sufficiently practical and useful when parameters k and m are small.

• Nuclear Medicine and Molecular Imaging
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• 제43권5호
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• pp.411-420
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• 2009

목적: 이 연구의 목적은 갑상선유두암 환자를 대상으로 재발의 진단에서 $^{18}F$-FDG PET/CT와 경부초음파검사를 함께 시행하는 것에 대한 유용성을 평가하고자 한다. 대상 및 방법: 2006년 12월부터 2008년 4월까지 갑상선유두암으로 갑상선 전절제술 및 고용량의 방사성옥소 치료를 시행 받은 환자 중에서 재발이 의심되어 $^{18}F$-FDG PET/CT를 시행한 51명(91건)을 대상으로 후향적으로 연구를 진행하였다. 의심되는 병소는 조직검사를 시행하였고, 조직 검사 결과와 PET 검사결과. PET/CT 검사결과, 경부초음파검사 결과를 비교하였다. 결과: $^{18}F$-FDG PET/CT (여자 57명, 남자 4명; 연령 범위, 24-81세, 평균 49세; 유두암 61개)의 민감도, 특이도, 정확도는 각각 환자 기준으로 87.2%, 59.0%, 77.0%였고, 병소 기준으로 92.3%, 64.1%, 80.2% 였다. $^{18}F$-FDG PET의 민감도, 특이도, 정확도는 각각 환자 기준으로 71.8% (P=0.03), 59.0% (p=1.00), 67.2% (p=0.03)였고, 병소 기준으로 78.8% (p=0.01), 64.1% (p=1.00), 72.5% (p=0.02)였다. 경부초음파검사의 경우 민감도, 특이도, 정확도는 각각 환자 기준으로 71.1% (p=0.07), 52.2% (p=0.75), 63.9% (p=0.08)였고, 병소 기준으로 71.2% (P<0.01), 61.5% (P=1.00), 67.0% (P=0.06)였다. $^{18}F$-FDG PET/CT 와 경부초음파검사를 함께 판독한 경우 민감도, 특이도, 정확도는 각각 환자 기준으로 94.7% (p=0.50), 82.6% (p=0.13), 90.2% (p=0.03)였고, 병소 기준으로 96.2% (p=0.50), 89.7% (p<0.01), 93.4% (p<0.01)였다. 결론: $^{18}F$-FDG PET/CT는 갑상선유두암의 재발 진단에서)$^{18}F$-FDG PET와 경부초음파검사와 비교하여 높은 민감도, 특이도, 정확도를 보였다. 게다가 $^{18}F$-FDG PET와 경부 초음파를 함께 시행한 경우 갑상선유두암의 재발 진단에 있어서 더욱 향상된 민감도, 특이도, 정확도를 보였다.

• 한국전자파학회논문지
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• 제23권2호
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• pp.169-176
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• 2012

본 논문에서는 전계 적분 방정식 (Electric Field Integral Equation: EFIE)을 사용하는 모멘트 법의 저주파 오차(low frequency breakdown) 문제를 해결하기 위한 방법으로 루프-스타(loop-star) 기저 함수를 사용하였다. 또한, 모멘트 법의 해를 계산하기 위하여 conjugate gradient method(CGM)과 같은 반복법을 적용할 경우 반복 횟수를 줄이기 위한 기법으로 p-Type Multiplicative Schwarz preconditioner(pMUS)를 이용하였다. 헬름홀쯔 정리(Helmholtz theorem)에 기반한 루프-스타(loop-star) 기저 함수와 주파수 정규화 기법을 이용하여 전계 적분 방정식에서 Rao-Wilton-Glisson(RWG) 기저 함수를 사용하였을 때 발생하는 저주파 오차(low frequency instability) 문제를 해결할 수 있다. 하지만, RWG 기저 함수를 비발산(solenoidal) 성분과 비회전성(irroatational) 성분으로 분해함으로써 발생하는 행렬 방정식의 높은 조건 수(condition number)로 인하여 CGM과 같은 반복법을 사용할 경우 해를 계산하기 위하여 많은 반복 횟수가 요구된다. 본 논문에서는 이러한 문제점을 해결하기 위한 방안으로 pMUS 전제 조건 기법을 이용하여 CGM의 반복 횟수를 줄였다. 수치 해석 결과, pMUS와 같은 희소성(sparsity)을 가진 블럭 대각 전제 조건(Block Diagonal Precondtioner: BDP)과 비교하였을 때 pMUS는 BDP보다 빠르게 해를 계산할 수 있다.

• Journal of Power Electronics
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• 제11권6호
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• pp.922-930
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• 2011

In this paper, two radial basis function neural networks (RBFNNs) are used to dynamically identify harmonics content in converter waveforms based on the p-q (real power-imaginary power) theory. The converter waveforms are analyzed and the types of harmonic content are identified over a wide operating range. Constant power and sinusoidal current compensation strategies are investigated in this paper. The RBFNN filtering training algorithm is based on a systematic and computationally efficient training method called the hybrid learning method. In this new methodology, the RBFNN is combined with the p-q theory to extract the harmonics content in converter waveforms. The small size and the robustness of the resulting network models reflect the effectiveness of the algorithm. The analysis is verified using MATLAB simulations.

• 통상정보연구
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• 제10권2호
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• pp.283-304
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• 2008

According to globalization and localization of world economics international trade payment method was also changed. A traditional payment was Letter of Credit basis, however it is being increased to various methods such as remittance, documentary collection(D/P, D/A) and open account. In order to acquire a secure export payment, exporters prefer to L/C basis which is guaranteed by a reliable bank. However, the L/C should bear a security so that importers would rather documentary collection than L/C. The reasons for the preference of collection payment rather than L/C are a low commission cost, the conversion of buyer's market from seller's market due to severe competition in the world market, transaction increase between main office and branches and a right to control the goods until executing the payment by exporters. Besides of them, collection payment can handle safer and faster than open account basis. However, the collection payment has a risk which it isn't guaranteed by bank for the payment so that I would suggest countermeasures to minimize the payment risk utilizing the collection basis as follows; using export credit insurance system, a large domestic credit report provider such as D&B for absolutely fresh and new information, a collection proxy service for overseas deferred credit and suggestion specifying to order B/L not straight one on consignee in order to transfer the right of ownership with endorsement without problem.