• 정보처리학회논문지B
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• 제12B권4호
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• pp.429-436
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• 2005

본 논문에서는 유전자 알고리즘의 일반적인 문제점인 과도한 저장공간의 소모와 탐색의 비효율성을 줄이기 위해 PBIL을 이용한 단순한 스테레오 정합 기법을 제안한다. PBIL은 확률벡터에 기반해서 통계적 탐색과 경쟁학습을 이용하는 변종 유전자 알고리즘이며 확률벡터의 사용으로 인해 직렬 및 병렬 유전자 알고리즘군에 비해 단순한 구조를 가진다. 본 논문에서는 이 PBIL을 스테레오 정합 환경에 맞게 변형 및 단순화시켜 정합 알고리즘을 개발한다. 높은 적응성을 갖는 염색체는 생존 확률 또한 높다는 진화 법칙을 보존하면서 유전자 풀, 염색체 교차 및 유전자 돌연변이를 제거할 수 있으며 그 결과 저장공간을 줄이고 정합 규칙을 간소화하여 계산 비용을 감소시킬 수 있다. 추가적으로 다해상도 정합 기법처럼 넓은 영역의 변이 일관성을 획득하기 위해 변이 연속성에 대한 이웃들의 거리를 제어하는 방식을 추가하여 고정된 작은 정합창을 사용하면서 안정된 결과를 얻을 수 있게 한다. 마지막으로 단순한 시스템에 적용될 수 있게 하기 위해서 확률벡터를 사용하지 않는 제안한 알고리즘의 소형 대안 기법을 제시한다.

• Smart Structures and Systems
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• 제4권5호
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• pp.605-628
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• 2008

In bridge structures, damage may induce an additional deflection which may naturally contain essential information about the damage. However, inverse mapping from the damage-induced deflection to the actual damage location and severity is generally complex, particularly for statically indeterminate systems. In this paper, a new load concept, called the positive-bending-inspection-load (PBIL) is proposed to construct a simple inverse mapping from the damage-induced deflection to the actual damage location. A PBIL for an inspection region is defined as a load or a system of loads which guarantees the bending moment to be positive in the inspection region. From the theoretical investigations, it was proven that the damage-induced chord-wise deflection (DI-CD) has the maximum value with the abrupt change in its slope at the damage location under a PBIL. Hence, a novel damage localization method is proposed based on the DI-CD under a PBIL. The procedure may be summarized as: (1) identification of the modal flexibility matrices from acceleration measurements, (2) design for a PBIL for an inspection region of interest in a structure, (3) calculation of the chord-wise deflections for the PBIL using the modal flexibility matrices, and (4) damage localization by finding the location with the maximum DI-CD with the abrupt change in its slope within the inspection region. Procedures from (2)-(4) can be repeated for several inspection regions to cover the whole structure complementarily. Numerical verification studies were carried out on a simply supported beam and a three-span continuous beam model. Experimental verification study was also carried out on a two-span continuous beam structure with a steel box-girder. It was found that the proposed method can identify the damage existence and damage location for small damage cases with narrow cuts at the bottom flange.

• 한국항공우주학회지
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• 제30권1호
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• pp.20-27
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• 2002

항공기의 설계는 공력, 구조, 조정성등 여러 가지 단위 기술들을 모두 고려하여야 하며, 성능의 향상을 위해서는 각각의 단위 기술들이 보다 정확해야하며, 단위 기술들의 상호작용이 고려되어야 한다. 본 연구에서는 이런 단위 기술 중 항공기 성능에 가장 중요한 영향을 주는 공력과 구조를 전산유체역학(CFD)기법과 유한요소법(FEM)을 사용하여 보다 정확히 해석하고자 하였으며, 설계의 안전성을 위해 공력과 구조의 상호작용인 공탄성 효과를 고려하였다. 최적화 알고리즘으로는 전역최적해를 구하기 위해 유전 알고리즘의 일종인 PBIL 알고리즘을 사용하였으며, PBIL 알고리즘 자체를 병렬화하여 과도한 계산 시간을 줄이고자 하였다. 현재의 설계방법의 정확성과 효율성을 검증하기 위해 주어진 항공기 날개에 대하여 설계를 수행하였다.

• 한국측량학회지
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• 제30권6_2호
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• pp.623-629
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• 2012

During the construction of crossing engineering one of the important measures to ensure the safety of subway operation is the implementation of deformation surveying to the existing subway tunnel. Guangzhou new subway line 2 engineering which crosses the existing tunnel is taken as the background. How to achieve intelligent and automatic deformation surveying forecast during the subway tunnel construction process is studied. Because large amount of surveying data exists in the subway construction, deformation analysis is difficult and prediction has low accuracy, a subway intelligent deformation prediction model based on the PBIL and support vector machine is proposed. The PBIL algorithm is used to optimize the exact key parameters combination of support vector machine though probability analysis and thereby the predictive ability of the model deformation is greatly improved. Through applications on the Guangzhou subway across deformation surveying deformation engineering the prediction method's predictive ability has high accuracy and the method has high practicality. It can support effective solution to the implementation of the comprehensive and accurate surveying and early warning under subway operation conditions with the environmental interference and complex deformation.

• 대한전자공학회논문지SP
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• 제38권5호
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• pp.538-547
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• 2001

최근 2차원 실시간 영상통신기술들이 급속한 발전을 거듭하여 여러 제품에 상용화되고 있는 추세이다. 그러나 이 기술들은 2차원 영상의 시각적 전송이므로 가상현실의 도래로 인해 수반된 3차원 현실감을 다루기에는 불충분하다고 할 수 있다. 이밖에 컴퓨터 그래픽 분야의 3차원 가상현실 연구가 합성 영상에 국한되어 연구되어졌기 때문에 실 영상에 대한 가상현실의 구현이 어려운 실정이다 그러므로 본 논문에서는 스테레오 시각을 이용하여 실 영상 가상현실 구현에 적용될 수 있는 유전자 알고리즘 기반의 새로운 3차원 객체 추출기법을 제시한다. 제안한 방법은 저장공간의 낭비와 알고리즘의 복잡성을 줄이기 위해서 확률벡터와 반복학습에 기반한 개체군기반 증가 학습이라는 소형 유전자 알고리즘을 정합 환경에 맞게 변형시켰다. 그 결과 정합 성능이 기존의 스테레오 정합 기법보다 우수하며, 간단하고 빠른 정합 알고리즘을 제시할 수 있었다. 또한, 영상의 특성에 무관하게 알고리즘의 변경 없이 안정된 결과를 얻을 수 있다는 장점이 있었다.

• 한국정보과학회논문지:시스템및이론
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• 제31권1_2호
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• pp.59-66
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• 2004

본 논문에서는 2차원 영상에서 3차원 깊이정보를 추출하기 위해서 진화연산 알고리즘을 적용한 고속 3차원 모델 추출 기법을 제안한다. 진화연산 알고리즘은 자연 선택과 개체군 유전학에 기반 한 생물학적 진화 과정을 통해 최적의 해를 찾는 효율적인 탐색 기법이다. 기존의 스테레오 정합 방법에서 생성되어진 2차원 깊이 정보인 변이 맵은 경계 부근에서 애매한 결과를 도출함으로써 변이의 세밀하고 정확한 정보를 잃어 실 영상과는 다소 차이를 갖는다. 본 논문에서는 소형 유전자 알고리즘을 스테레오 정합환경에 맞게 변형시키고, 생성된 변이 맵의 모호성을 해결하기 위해 이전 세대의 변이 맵으로부터 경계를 검출한 변이 경계정보에서 이웃한 화소의 변이 복잡도를 측정하여 복잡도에 따라 적응적 윈도우를 결정하여 정합에 사용하였다. 실험을 통해 제안한 방식이 이완 처리를 포함한 기존의 정합 방식보다 변이 맵 생성에 있어 보다 상세하고 매끄러운 변이 결과를 얻을 수 있었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.474-478
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• 1999

Genetic algorithm is an efficient search method using principles of natural selection and population genetics. In conventional genetic algorithms, however, the size of gene pool should be increased to insure a convergency. Therefore, many memory spaces and much computation time were needed. Also, since child chromosomes were generated by chromosome crossover and gene mutation, the algorithms have a complex structure. Thus, in this paper, a compact stereo matching algorithm using a population-based incremental teaming based on probability vector is proposed to reduce these problems. The PBIL method is modified for matching environment. Since the Proposed algorithm uses a probability vector and eliminates gene pool, chromosome crossover, and gene mutation, the matching algorithm is simple and the computation load is considerably reduced. Even if the characteristics of images are changed, stable outputs are obtained without the modification of the matching algorithm.

• Journal of Information Processing Systems
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• 제5권2호
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• pp.105-116
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• 2009

To solve the general problems surrounding the application of genetic algorithms in stereo matching, two measures are proposed. Firstly, the strategy of simplified population-based incremental learning (PBIL) is adopted to reduce the problems with memory consumption and search inefficiency, and a scheme for controlling the distance of neighbors for disparity smoothness is inserted to obtain a wide-area consistency of disparities. In addition, an alternative version of the proposed algorithm, without the use of a probability vector, is also presented for simpler set-ups. Secondly, programmable graphics-hardware (GPU) consists of multiple multi-processors and has a powerful parallelism which can perform operations in parallel at low cost. Therefore, in order to decrease the running time further, a model of the proposed algorithm, which can be run on programmable graphics-hardware (GPU), is presented for the first time. The algorithms are implemented on the CPU as well as on the GPU and are evaluated by experiments. The experimental results show that the proposed algorithm offers better performance than traditional BMA methods with a deliberate relaxation and its modified version in terms of both running speed and stability. The comparison of computation times for the algorithm both on the GPU and the CPU shows that the former has more speed-up than the latter, the bigger the image size is.

• Advances in Computational Design
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• 제6권1호
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• pp.31-42
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• 2021

This research aims to demonstrate the optimal geometrical design of splayed multiple cross-sectional pin fin heat sinks (SMCSPFHS), which are a type of side-inlet-side-outlet heat sink (SISOHS). The optimiser strength Pareto evolutionary algorithm2 (SPEA2)is employed to explore a set of Pareto optimalsolutions. Objective functions are the fan pumping power and junction temperature. Function evaluations can be accomplished using computational fluid dynamics(CFD) analysis. Design variablesinclude pin cross-sectional areas, the number of fins, fin pitch, thickness of heatsink base, inlet air speed, fin heights, and fin orientations with respect to the base. Design constraints are defined in such a way as to make a heat sink usable and easy to manufacture. The optimum results obtained from SPEA2 are compared with the straight pin fin design results obtained from hybrid population-based incremental learning and differential evolution (PBIL-DE), SPEA2, and an unrestricted population size evolutionary multiobjective optimisation algorithm (UPSEMOA). The results indicate that the splayed pin-fin design using SPEA2 issuperiorto those reported in the literature.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2005년도 국제학술심포지움 The 44th Annual Meeting of Korean Society for Life Science
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• pp.23-36
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• 2005

Bax, a mammalian pro-apoptotic member of the Bcl-2 family, induces cell death when expressed In yeast. To investigate whether .Bax expression can induce cell death in plant, we produced transgenic Arabidopsis plants that contained murine Bax cDNA under control of a glucocorticoid-inducible promoter. Transgenic plants treated with dexamethasone, a strong synthetic glucocorticoid, induced Bax accumulation and cell death, suggesting that some elements of cell death mechanism by Bax may be conserved among various orgarusms. Therefore, we developed novel yeast genetic system, and cloned several Plant Bax Inhibitors (PBIs). Here, we report the function of two PBIs In detail. PBIl is ascorbate peroxidase (sAPX). Fluorescence method of dihydrorhodamine123 oxidation revealed that expression of Bax in yeast cells generated reactive oxygen species (ROS), and which was greatly reduced by co-expression with sAPX. These results suggest that sAPX inhibits the generation of ROS by Bax, which in turn suppresses Bax-induced cell death in yeast. PBI2 encodes nucleoside diphosphate kinase (NDPK). ROS stress strongly induces the expression of the NDPK2 gene in Arabidopsis thaliana (AtNDPK2). Transgenic plants overexpressing AtNDPK2 have lower lovels of ROS than wildtype plants. Mutants lacking AtNDPK2 had higher levels of ROS than wildtype. H$_{2O2}$ treatment induced the phosphorylation of two endogenous proteins whose molecular weights suggested they are AtMPK3 and AtMPK6. In the absence of H2O2 treatment, phosphorylation of these proteins was slightly elevated in plants overexpressing AtNDPK2 but markedly decreased In the AtNDPK2 deletion mutant. Yeast two-hybrid and in vitro protein pull-down assays revealed that AtNDPK2 specifically interacts with AtMPK3 and AtMPK6. Furthermore, AtNDPK2 also enhances the MBP phosphorylation activity of AtMPK3 i'n vitro. Finally, constitutive overexpression of AtNDPK2 in Arabidopsis plants conferred an enhanced tolerance to multiple environmental stresses that elicit ROS accumulation In situ. Thus, AtNDPK2 appears to play a novel regulatory role in H2O2-mediated MAPK signaling in plants.