• Kyungpook Mathematical Journal
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• 제48권2호
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• pp.303-315
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• 2008

In [8] M. Y. Alzoubi and M. M. Jaradat studied the basis number of the composition of paths and cycles with Ladders, Circular ladders and M$\"{o}$bius ladders. Namely, they proved that the basis number of these graphs is 4 except possibly for some cases in each of them. Since the lexicographic product is noncommutative, in this paper we investigate the basis number of the lexicographic product of the different kinds of ladders with paths and cycles. In fact, we prove that the basis number of almost all of these graphs is 4.

• Kyungpook Mathematical Journal
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• 제47권2호
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• pp.165-714
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• 2007

The basis number of a graph G is the least positive integer $k$ such that G has a $k$-fold basis. In this paper, we prove that the basis number of the cartesian product of a path with a circular ladder, a M$\ddot{o}$bius ladder and path with a net is exactly 3. This improves the upper bound of the basis number of these graphs for a general theorem on the cartesian product of graphs obtained by Ali and Marougi, see [2]. Also, by this general result, the cartesian product of a theta graph with a M$\ddot{o}$bius ladder is at most 5. But in section 3 we prove that it is at most 4.

• 대한수학회보
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• 제44권3호
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• pp.385-394
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• 2007

An upper bound of the basis number of the semi-strong product of cycles with bipartite graphs is given. Also, an example is presented where the bound is achieved.

• Kyungpook Mathematical Journal
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• 제45권1호
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• pp.45-53
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• 2005

A basis of the cycle space C (G) is d-fold if each edge occurs in at most d cycles of C(G). The basis number, b(G), of a graph G is defined to be the least integer d such that G has a d-fold basis for its cycle space. MacLane proved that a graph G is planar if and only if $b(G)\;{\leq}\;2$. Schmeichel showed that for $n\;{\geq}\;5,\;b(K_{n}\;{\bullet}\;P_{2})\;{\leq}\;1\;+\;b(K_n)$. Ali proved that for n, $m\;{\geq}\;5,\;b(K_n\;{\bullet}\;K_m)\;{\leq}\;3\;+\;b(K_n)\;+\;b(K_m)$. In this paper, we give an upper bound for the basis number of the semi-strong product of a bipartite graph with a cycle.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.52-57
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• 2001

In this paper, the optimum designs of air-bearing surface(ABS) are achieved effectively by using reduced basis concept which can reduce the number of design variables although the design space is distended. Generally, the optimization method is more effective than the trial and error. However, the efficiency of the former is largely dependent on the number of the design variables. In order to reduce the number of design variables and increase the efficiency, reduced basis concept is applied. We can define the desired design as a linear combination of basis designs using this concept. From this optimization method with reduced basis concept, we easily obtain the optimum designs of ABS whose target flying heights are 25, 20, 15 nm.

• 한국응급구조학회지
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• 제7권1호
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• pp.55-64
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• 2003

The purposes of this study which was conducted by applying three projection formulae to the data from admission quota for paramedic of the Ministry of Education & Human Resources Development the number of ambulances the number of emergency medical centers of the Ministry of Health & Welfare and rate of successful candidates of annual report of the National Health Personnel Licensing Examination Board were to find out demand and supply of paramedic from 2002 to 2045 and to expand scope of practice of paramedic in Korea. The conclusions from this study were summarized as follows; (1) The simple formulae derived from the projection formula of the Economic Planning Board were applied under the present Emergency Medical Services Act including qualifying over 3-years experienced EMT-Basic for paramedic examinee, stationing paramedic or EMT-Basic or physician or nurse per ambulance, stationing paramedic or EMT-Basic per emergency medical center and under the amended Emergency Medical Services Act including qualifying only paramedic graduate for paramedic examinee, stationing 4.5 paramedics per ambulance, stationing 10 to 2 paramedics per emergency medical center. (2) It was estimated that on the American basis of 5.6 EMTs per 10,000 in 1996, the number of paramedics under the present act will reach the basis before 2020, the number of paramedics under the amended act will reach the basis about 2040. (3) It was estimated that on the basis of 22,000 paramedics demanded from the number of ambulances, the number of emergency medical centers in 2001, the number of paramedics under the present act will reach the basis before 2015, the number of paramedics under the amended act will reach the basis about 2030. (4) There was relationship between requirements for emergency medical centers scope of practice of paramedic in the act and demand-supply of paramedic, this necessitates surveys, studies, amendment of the act, legalization for expanded scope of practice of paramedic including EMD, instructor, teacher of safety. (5) This study which includes only expanded scope of practice of paramedic and projection for paramedic in the act needs complementary studies such as decision-making process in health manpower policy and so on.

• 대한기계학회논문집A
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• 제27권3호
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• pp.343-348
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• 2003

In this study, optimum designs of the air-bearing surface (ABS) are achieved using the reduced basis concept which can effectively reduce the number of design variables without cutting down on the design space. Even though the optimization method is easier and more applicable to handle than the trial-and-error method, its efficiency is largely dependent on the number of the design variables. Hence, the reduced basis concept is applied, by which the desired design can be defined as a linear combination of basis designs. The simulation results show the effectiveness of the proposed approach by obtaining the optimum solutions of the sliders whose target flying heights are 25, 20, and 15nm.

• 경영과학
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• 제13권3호
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• pp.105-113
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• 1996

Constructing an initial basis is an important process in the simplex method. An initial basis greatly affects the number of iterations of iterations and the execution time in the simplex method. The purpose of this paper is to construct a good initial basis. First, to avoid linear dependency among the chosen columns, an enhanced Gaussian elimination method and a method using non-duplicated nonzero elements are developed. Second, for an order to choose variables, the sparsity of the column is used. Experimenal results show that the proposed method can reduce the number of iterations and the execution time compared with Bixby's method by 12%.

• 경영과학
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• 제17권2호
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• pp.13-20
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• 2000

In this research, we compare and analyze the two initial basis construction procedures: LPAKO’s procedure proposed by Seo et. al. and symbolic crash procedure proposed by Maros et. al.. Based on the analysis, we present a new procedure which complements the previous procedures. The new procedure shows superiority to the previous procedures with respects to the optimality of initial basis. Also, the linear basis Also. the initial basis constructed by the new procedure reduces the number of simplex iterations.

• 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.