• Journal of applied mathematics & informatics
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• 제22권1_2호
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• pp.339-350
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• 2006

The bifurcation point where a satellite component buds from another component is characterized by the existence of the common tangent line between the two osculating components appearing in the degree-n bifurcation set. We investigate the existence, location and number of bifurcation points for satellite components budding from the main component in the degree-n bifurcation set as well as a parametric boundary equation of the main component of the degree-n bifurcation set. Cusp points are also located on the boundary of the main component. Typical degree-n bifurcation sets and their components are illustrated with some computational results.

• 대한한의학회지
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• 제23권4호
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• pp.45-54
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• 2002

Objectives: In order to investigate the relationship of Radix Trichosanthis components and the melanin synthesis, the author has analyzed the cell viability and tyrosinase activity, melanin content and morphologic changes in n-hexane, EtOAc, n-BuOH, and H2O fraction. Methods: At first, in order to determine the concentration of the Radix Trichosanthis component, the author investigated the viability of B16 melanoma cell. To measure the effects of Trichosanthes kirilowii extracts (n-BuOH, n-Hexane, EtOAc, H2O fractions) on the viability of A549 cells, A549 cells were treated with various concentrations (from 0.5 to $25{\;}\mu\textrm{g}/ml$) of components of Trichosanthes kirilowii. After 24hrs, the cell viability was measured by MTT assay. The EtOAc components of Trichosanthes kirilowii decreased the viability of A549 cells in a dose-dependent manner. H2O and n-BuOH components had no cell toxicity till $25{\;}\mu\textrm{g}/ml$, the n-hexane component showed minor cell toxicity at $25{\;}\mu\textrm{g}/ml$ and the EtOAc component cell toxicity was revealed at $5{\;}\mu\textrm{g}/ml$ concentration. Results: 1. The results of tyrosinase activity and the Radix Trichosanthis component; n-hexane and EtOAc components controlled it effectively; the n-BuOH components were less effective. 2. The results of melanin content analysis showed that the n-hexane and EtOAc components effectively inhibited, the n-BuOH fraction inhibited less, and H2O component didn't inhibit the terminal melanin formation. 3. In the n-BuOH and H2O component there were no changes, but in the n-hexane component the melanin content was effectively inhibited. 4. In the EtOAc fraction, although the melanin content was inhibited, the cell count was evidently suppressed, Of all of the Radix Trichosanthis components, the n-Hexane and EtOAc fractions inhibited the melanin synthesis best, but owing to its toxicity, the EtOAc components inhibited the cell count. Conclusion: The above results demonstrated that Radix Trichosanthis n-hexane fraction efficiently inhibited the tyrosinase activity and melanin synthesis.

• 한국정보과학회논문지:소프트웨어및응용
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• 제28권9호
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• pp.629-633
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• 2001

본 논문에서는 독립 성분 해석(Independent Component Analysis, ICA) 기법과 정규화를 이용한 영상분류 방법을 제안한다. 이 제안된 방법은 전처리 없이 ICA나 주성분 해석(Principal Component Analysis, PCA)을 이용한 것에 비해 잡음에 대한 강인성을 증가시킨다. 영상에 잡음이 인가된 경우, CPA는 N(0, 0.4), ICA는 N(0.53)까지이 분류가 가능함을 보이는 반면에 비해, 제안된 정규화 전처리는 N(0, 0.75)까지 영상분류가 됨을 실험에서 보이고 있다.

• Journal of the Korean Statistical Society
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• 제20권1호
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• pp.67-76
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• 1991

The empirical Bayes version involves ″independent″ repetitions(a sequence) of the component decision problem. With the varying sample size possible, these are not identical components. However, we impose the usual assumption that the parameters sequence $\theta$=($\theta$$_1$, $\theta$$_2$, …) consists of independent G-distributed parameters where G is unknown. We assume that G $\in$ g, a known family of distributions. The sample size $N_i$ and the decisin rule $d_i$ for component i of the sequence are determined in an evolutionary way. The sample size $N_1$ and the decision rule $d_1$$\in$ $D_{N1}$ used in the first component are fixed and chosen in advance. The sample size $N_2$and the decision rule $d_2$ are functions of *see full text($\underline{X}^1$equation omitted), the observations in the first component. In general, $N_i$ is an integer-valued function of *see full text(equation omitted) and, given $N_i$, $d_i$ is a $D_{Ni}$/-valued function of *see full text(equation omitted). The action chosen in the i-th component is *(equation omitted) which hides the display of dependence on *(equation omitted). We construct an empirical Bayes decision rule for estimating normal mean and show that it is asymptotically optimal.

• Journal of applied mathematics & informatics
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• 제16권1_2호
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• pp.221-229
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• 2004

It is known that the parametric boundary equation for the main component in the Mandelbrot set represents a cardioid. We derive an epicy-cloidal boundary equation of the main component in the degree-n bifurcation set by extending the parameter which describes the cardioid in the Mandelbrot set. Computational results as well as some useful properties are presented together with the programming source codes written in Mathematica. Various boundaries are displayed for $2\leqn\leq7$7 and show a good agreement with the theory presented here. The known boundary equation enables us to significantly reduce the construction time for the degree-n bifurcation set.

• 대한산업공학회지
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• 제21권4호
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• pp.629-638
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• 1995

It is shown that the reliability function of an n-component parallel system is equivalent to that of n-component stand-by system if we increase the exponential failure rates of the parallel system's components in proportion to the increasing load per surviving component.

• 응용통계연구
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• 제8권1호
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• pp.51-60
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• 1995

크기가 $n \times p$인 자료행렬에서 p개의 변수들과 성격이 다소 다른 $p_s$개의 변수를 같이 고려한 크기가 $n \times (p + p_s)$ 자료행렬이 있다 하자. 전통적 주성성분분석은 성격이 다른 변수들로 인하여 효과적인 결과를 제공하지 못한다. 본 논문에서는 이런 점을 개선하기 위해서 성격이 다른 $p_s$개의 변수를 추가변수로 두는 추가적 주성분분석을 소개하려 한다. 이 기법은 전통적 주성분분석의 대수적,기하적인 면을 따른다. 그리고 전통적 주성분분석과 추가적 주성성분분석을 활용한 한국 프로야구의 8개팀과 1982-1992년 동안의 14개의 부문별 기록에 대한 전형적인 자료분석의 한 예를 제시한다. 더불어 두 분석의 결과도 비교하였다.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1987년도 제21차 학술대회 연제순서 및 초록
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• pp.7.2-7
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• 1987

Waver 와 Bray (1930) 가 cochlear microphonic을 처음 발견한 이래 Derbyshire 와 Davis (1935)는 summating potential을 각각 처음 기술하여 이 세가지 전위를 electrocochleogram 이라 칭하였고 이는 감음신경성 난청의 감별진단 및 청각생리연구에 이용되어 왔다. 저자들은 정상 guinea pig 10 마리를 대상으로 DANAC 7E ERA청각계기를 사용하여 정원창에서 action potential과 summating potential을 측정하였으며 주파수에 따른 역치 자극간 간격 및 두 potential의 상호관계를 분석하여 다음과 같은 결과를 얻었다. 1) 주파수가 증가함에 따라 그 역치는 점차 감소하였다. 2) 자극음의 강도와 action potential의 $N_1$ component 진폭은 상호 비례관계를 보여 주었으며 주파수 증가에 따라 $N_1$ component 진폭은 점차 증가하였다. 3) Action potential 의 $N_1$ component latency는 주파수가 증가할수록 역비례 관계를 보여 주었다. 4) N$_1$ component의 진폭과 자극간 간격(interstimulus interval, ISI)과의 관계는 ISI가 80~160m sec사이에서 plateau를 형성하였다. 5) summating potential은 자극음의 강도가 증가함에 따라 그 진폭이 증가하였으며 action potential도 증가하였으나, SP/AP는 감소하는 경향을 보였다.

• 산업공학
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• 제23권4호
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• pp.327-336
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• 2010

We consider a supply chain consisting of a make-to-order manufacturer and N component suppliers and study the impacts of the number of suppliers on component inventory management. The manufacturer has full information and continuously observes the state of both component inventory level and customer backorders. Based on this information, the manufacturer determines whether or not to place a component purchasing order to a supplier among N suppliers even though some orders are in process by other suppliers. The goal of this paper is to numerically identify the manufacturer's purchasing policy which minimizes the total supply chain cost and the best choice of N. Our model contributes to the current literature in that the problem of simultaneously considering multiple outstanding orders and incorporating order setup cost into the model has not been covered yet. From numerical experiment, we investigate how much the policy with N suppliers can contribute to reducing the supply cost compared to the policy with a single supplier.

• Journal of applied mathematics & informatics
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• 제10권1_2호
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• pp.63-73
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• 2002

The governing equation locating component centers in the degree-n bifurcation set is a polynomial with a very high degree and its root-finding lacks numerical accuracy. The equation is transformed to have its degree reduced by a factor(n-1). Newton's method applied to the transformed equation improves the accuracy with properly chosen initial values. The numerical implementation is done with Maple V using a large number of computational precision digits. Many cases are studied for 2 $\leq$ n $\leq$ 25 and show a remarkably improved computation.