• 한국융합학회논문지
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• 제10권11호
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• pp.71-77
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• 2019

본 연구에서는 다중 선택 배낭 모형의 최적해를 찾는 해법을 제시하고자 한다. 다중 선택은 동일한 집단에 소속된 구성원들이 동시에 선택되거나 동시에 배제되는 상황에서 관찰된다. 각 집단 간 관련성의 측정치인 오목 함수가 의사결정기준으로 설정되었다. 다중 선택은 비선형 제약식으로 모형화 되는데 일반 배낭 제약식으로 변환될 수 있다. 따라서 최적 해법 개발을 위해 오목함수 최소화 문제와 배낭 문제의 일반적인 해법들에서 채택하고 있는 분지 한계 접근법을 이용하였다. 단체상에서 오목함수를 가장 근접하게 하한추정하는 함수가 1차식이라는 사실이 한계 전략의 이론적 토대가 된다. 또한 하위 단계에서도 1차식 목적함수가 유일하게 결정되도록, 후보 단체를 두 개의 초평면에 투사시킴으로써 1차원 낮은 두 개의 하위 단체로 분할하는 방법이 분지 전략의 핵심이다. 앞으로 본 연구의 결과는 다양한 형태의 배낭 제약식 하에서의 오목 함수 최소화 문제의 해법을 개발하는데 응용될 수 있을 것이다.

• Journal of applied mathematics & informatics
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• 제30권3_4호
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• pp.477-488
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• 2012

The convergence rate of a numerical procedure based on Schwarz Alternating Method(SAM) for solving elliptic boundary value problems depends on the selection of the interface conditions applied on the interior boundaries of the overlapping subdomains. It has been observed that the mixed interface condition, controlled by a parameter, can optimize SAM's convergence rate. In [8], one introduced the two-layer multi-parameterized SAM and determined the optimal values of the multi-parameters to produce the best convergence rate for one-dimensional elliptic boundary value problems. In this paper, we present a method which utilizes the one-dimensional result to get the optimal convergence rate for the two-dimensional problem.

• Journal of applied mathematics & informatics
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• 제29권1_2호
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• pp.161-171
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• 2011

The convergence rate of a numerical procedure based on Schwarz Alternating Method(SAM) for solving elliptic boundary value problems depends on the selection of the interface conditions applied on the interior boundaries of the overlapping subdomains. It has been observed that the Robin condition (mixed interface condition), controlled by a parameter, can optimize SAM's convergence rate. In [7], one had formulated the multi-parameterized SAM and determined the optimal values of the multi-parameters to produce the best convergence rate for one-dimensional elliptic boundary value problems. However it was not successful for two-dimensional problem. In this paper, we present a new method which utilizes the one-dimensional result to get the optimal convergence rate for the two-dimensional problem.

• Journal of applied mathematics & informatics
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• 제9권1호
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• pp.101-124
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• 2002

The convergence rate of a numerical procedure barred on Schwarz Alternating Method (SAM) for solving elliptic boundary value problems (BVP's) depends on the selection of the interface conditions applied on the interior boundaries of the overlapping subdomains. It hee been observed that the Robin condition(mixed interface condition), controlled by a parameter, can optimize SAM's convergence rate. Since the convergence rate is very sensitive to the parameter, Tang[17] suggested another interface condition called over-determined interface condition. Based on the over-determined interface condition, we formulate the two-layer multi-parameterized SAM. For the SAM and the one-dimensional elliptic model BVP's, we determine analytically the optimal values of the parameters. For the two-dimensional elliptic BVP's , we also formulate the two-layer multi-parameterized SAM and suggest a choice of multi-parameter to produce good convergence rate .

• 한국육종학회지
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• 제41권4호
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• pp.560-563
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• 2009

"골든아이" 품종은 경남농업기술원 화훼연구소에서 분홍색 홑꽃인 "로사"를 모본, 백색 홑꽃인 "안개소국"을 부본으로 인공교배를 실시하여 2004에서 2008년에 걸쳐서 파종과 계통선발을 통해 육성하였다. 품종의 특성검정은 2006년부터 2008년까지 봄 촉성재배와 가을 억제재배 조건아래서 3회에 걸쳐 조사하였다. "골든아이" 품종의 자연개화기는 10월23일경으로 개화가 빠른 편이며, 일장조절에 의해 주년재배가 가능하다. 초장이 95.2 cm이고 꽃 크기가 2.4 cm인 산티니계의 스프레이국화로 착화수는 23.2개로 다화성품종이다. 화색은 황색이며, 개화형태는 산방화서이다. 봄의 단일상태에서 "골든아이" 품종의 개화소요일수는 49일 정도이며, 가을 절화수명검정에서 25.7일로 아주 긴 편이다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권9호
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• pp.4983-4988
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• 2013

Objectives: To establish a taxol-resistant cell line of human ovarian carcinoma (A2780/Taxol) and investigate its biological features. Methods: The drug-resistant cell line (A2780/Taxol) was established by continuous stepwise selection with increasing concentrations of Taxol. Cell morphology was assessed by microscopy and growth curves were generated with in vitro and in vivo tumor xenograft models. With rhodamine123 (Rh123) assays, cell cycle distribution and the apoptotic rate were analyzed by flow cytometry (FCM). Drug resistance-related and signal associated proteins, including P-gp, MRPs, caveolin-1, PKC-${\alpha}$, Akt, ERK1/2, were detected by Western blotting. Results: A2780/Taxol cells were established with stable resistance to taxol. The drug resistance index (RI) was 430.7. Cross-resistance to other drugs was also shown, but there was no significant change to radioresistance. Compared with parental cells, A2780/Taxol cells were significantly heteromorphous, with a significant delay in population doubling time and reduced uptake of Rh123 (p<0.01). In vivo, tumor take by A2780 cells was 80%, and tumor volume increased gradually. In contrast, with A2780/Taxol cells in xenograft models there was no tumor development. FCM analysis revealed that A2780/Taxol cells had a higher percentage of G0/G1 and lower S phase, but no changes of G2 phase and the apoptosis rate. Expression of P-gp, MRP1, MRP2, BCRP, LRP, caveolin-1, PKC-${\alpha}$, Phospho-ERK1/2 and Phospho-JNK protein was significantly up-regulated, while Akt and p38 MARK protein expression was not changed in A2780/Taxol cells. Conclusion: The A2780/Taxol cell line is an ideal model to investigate the mechanism of muti-drug resistance related to overexpression of drug-resistance associated proteins and activation of the PKC-${\alpha}/ERK$ (JNK) signaling pathway.