• 대한수학회지
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• 제37권5호
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• pp.687-705
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• 2000

The main purpose of this paper is to study differentiable one-parameter groups and cosine families of operators acting on white noise functions and their associated infinitesimal generators. In particular, we prove the heredity of differentiable one-parameter group and cosine family of operators under the second quantization of the Cuchy problems for the first and second or der differential equations.

• 대한수학회보
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• 제34권3호
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• pp.411-419
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• 1997

Using the theory of strongly continuous cosine families, we prove controllable of nonlinear second order control system and give an application.

• 대한수학회보
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• 제55권4호
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• pp.1065-1092
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• 2018

This manuscript is involved with a category of second-order impulsive functional integro-differential equations with nonlocal conditions in Banach spaces. Sufficient conditions for existence and approximate controllability of mild solutions are acquired by making use of the theory of cosine family, Banach contraction principle and Leray-Schauder nonlinear alternative fixed point theorem. An illustration is additionally furnished to prove the attained principles.

• Communications for Statistical Applications and Methods
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• 제24권6호
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• pp.663-671
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• 2017

Some genetic association tests include an unidentifiable nuisance parameter under the null hypothesis of no association. When the mode of inheritance (MOI) is not specified in a case-control design, the Cochran-Armitage (CA) trend test contains an unidentifiable nuisance parameter. The transmission disequilibrium test (TDT) in a family-based association study that includes the unaffected also contains an unidentifiable nuisance parameter. The hypothesis tests that include an unidentifiable nuisance parameter are typically performed by taking a supremum of the CA tests or TDT over reasonable values of the parameter. The p-values of the supremum test statistics cannot be obtained by a normal or chi-square distribution. A common method is to use a Davies's upper bound of the p-value instead of an exact asymptotic p-value. In this paper, we provide a unified sine-cosine process expression of the CA trend test that does not specify the MOI and the TDT that includes the unaffected. We also present a closed form expression of the exact asymptotic formulas to calculate the p-values of the supremum tests when the score function can be written as a linear form in an unidentifiable parameter. We illustrate how to use the derived formulas using a pharmacogenetics case-control dataset and an attention deficit hyperactivity disorder family-based example.

• 대한수학회보
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• 제48권4호
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• pp.813-838
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• 2011

In this paper, we prove sufficient conditions for controllability of second order semi-linear neutral impulsive differential inclusions on unbounded domain with infinite delay in Banach spaces using the theory of strongly continuous Cosine families. We shall rely on a fixed point theorem due to Ma for multi-valued maps. The controllability results in infinite dimensional space has been proved without compactness on the family of Cosine operators.

• 전기학회논문지
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• 제66권8호
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• pp.1272-1277
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• 2017

To assist radiologists for the characterization of breast masses, Computer-aided Diagnosis(CADx) system has been studied. The CADx system can improve the diagnostic accuracy of radiologists by providing objective information about breast masses. Morphological and texture features were extracted from the breast ultrasound images. Based on extracted features, the CADx system retrieves masses that are similar to a query mass from a reference library using a k-nearest neighbor (k-NN) approach. Eight similarity measures of distance, Euclidean, Chebyshev(Minkowski family), Canberra, Lorentzian($F_2$ family), Wave Hedges, Motyka(Intersection family), and Cosine, Dice(Inner Product family) are evaluated by ROC(Receiver Operating Characteristic) analysis. The Inner Product family measure used with the k-NN classifier provided slightly higher performance for classification of malignant and benign masses than those with the Minkowski, $F_2$, and Intersection family measures.

• Journal of applied mathematics & informatics
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• 제27권5_6호
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• pp.1145-1156
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• 2009

In this paper, we consider the existence, uniqueness of the solutions and controllability for the neutral functional integro-differential equations with delay terms by Sadovskii's fixed point theorem.

• 정보보호학회논문지
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• 제29권2호
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• pp.347-363
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• 2019

사람의 DNA가 변하지 않는 것과 같이 사이버상의 악성코드도 변하지 않는 고유의 행위 특징을 갖고 있다. APT(Advanced Persistent Threat) 공격에 대한 방어수단을 사전에 확보하기 위해서는 악성코드의 악성 행위 특징을 추출해야 한다. 이를 위해서는 먼저 악성코드 간의 유사도를 계산하여 유사한 악성코드끼리 분류할 수 있어야 한다. 본 논문에서는 Windows OS 상에서 동작하는 악성코드 간의 유사도 계산 방법으로 'TF-IDF 코사인 유사도', 'Nilsimsa 유사도', '악성코드 기능 유사도', 'Jaccard 유사도'를 사용해 악성코드의 유형을 예측해보고, 그 결과를 보인다. 실험결과, 유사도 계산 방식마다 악성코드 유형에 따라 예측률의 차이가 매우 컸음을 발견할 수 있었다. 모든 결과에 월등한 정확도를 보인 유사도는 존재하지 않았으나, 본 실험결과를 이용하여 특정 패밀리의 악성코드를 분류할 때 어떤 유사도 계산 방식을 활용하는 것이 상대적으로 유리할지를 결정할 때 도움이 될 것으로 판단된다.