• Title/Summary/Keyword: cluster method

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Assessment of the Performance of B2PLYP-D for Describing Intramolecular π-π and σ-π Interactions

  • Choi, Tae-Hoon;Han, Young-Kyu
    • Bulletin of the Korean Chemical Society
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    • v.32 no.12
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    • pp.4195-4198
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    • 2011
  • Intramolecular ${\pi}-{\pi}$ and ${\sigma}-{\pi}$ interactions are omnipresent for numerous energetic and structural phenomena in nature, and the exact description of these nonbonding interactions plays an important role in the accurate prediction of the three-dimensional structures for numerous interesting molecular systems such as protein folding and polymer shaping. We have selected two prototype molecular systems for benchmarking calculations of intramolecular ${\pi}-{\pi}$ and ${\sigma}-{\pi}$ interactions. Accurately describing conformational energy of such systems requires highly elaborate but very expensive ab initio methods such as coupled cluster singles, doubles, and (triples) (CCSD(T)). Our calculations reveal a double hybrid density functional incorporating dispersion correction (B2PLYP-D) that agrees excellently with the CCSD(T) results, indicating that B2PLYP-D can serve as a practical method of choice.

Microstructure and Magnetic State of Fe3O4-SiO2 Colloidal Particles

  • Kharitonskii, P.V.;Gareev, K.G.;Ionin, S.A.;Ryzhov, V.A.;Bogachev, Yu.V.;Klimenkov, B.D.;Kononova, I.E.;Moshnikov, V.A.
    • Journal of Magnetics
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    • v.20 no.3
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    • pp.221-228
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    • 2015
  • Colloidal particles consisted of individual nanosized magnetite grains on the surface of the silica cores were obtained by two-stage sol-gel technique. Size distribution and microstructure of the particles were analyzed using atomic force microscopy, X-ray diffraction and Nitrogen thermal desorption. Magnetic properties of the particles were studied by the method of the longitudinal nonlinear response. It has been shown that nanoparticles of magnetite have a size corresponding to a superparamagnetic state but exhibit hysteresis properties. The phenomenon was explained using the magnetostatic interaction model based on the hypothesis of iron oxide particles cluster aggregation on the silica surface.

Advanced Bounding Box Prediction With Multiple Probability Map

  • Lee, Poo-Reum;Kim, Yoon
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.12
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    • pp.63-68
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    • 2017
  • In this paper, we propose a bounding box prediction algorithm using multiple probability maps to improve object detection result of object detector. Although the performance of object detectors has been significantly improved, it is still not perfect due to technical problems and lack of learning data. Therefore, we use the result correction method to obtain more accurate object detection results. In the proposed algorithm, the preprocessed bounding box created as a result of object detection by the object detector is clustered in various form, and a conditional probability is given to each cluster to make multiple probability map. Finally, multiple probability map create new bounding box of object using morphological elements. Experiment results show that the newly predicted bounding box reduces the error in ground truth more than 45% on average compared to the previous bounding box.

Glitch Removal Method in Gate Level consider CPLD Structure (CPLD 구조를 고려한 게이트 레벨 글리치 제거 방법)

  • Kim, Jae-Jin
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2017.01a
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    • pp.145-146
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    • 2017
  • 본 논문에서는 CPLD 구조를 고려한 게이트 레벨 글리치 제거 방법에 대해 제안하였다. CPLD는 AND-OR 게이트의 2단 구조를 가진 LE를 기본 구조로 구성되어 있는 소자이다. CPLD로 구현할 회로에 대한 DAG를 CPLD 구조에 맞도록 그래프를 분할하여 매핑가능클러스터를 생성한다. 생성된 매핑가능클러스터는 내부의 글리치와 전체 회로에 대한 글리치 발생 가능성을 검사하여 글리치를 제거한다. AND게이트와 OR게이트를 사용하는 2단 구조는 게이트가 달라 글리치가 발생될 수 있는 가능성을 검사하기 어렵다는 단점이 있어 AND-OR 게이트의 2단 구조와 동일한 구조를 가지고 있으며 게이트가 동일한 NAND 게이트를 이용하여 전체 회로를 변환한 후 글리치 발생여부를 검사함으로서 정확한 글리치 발생 가능성을 제거한다. 실험 결과는 제안 된 알고리즘 [10]과 비교하였다. 소비 전력이 2 % 감소되어 본논문에서 제안한 방법의 효율성이 입증되었다.

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Development and application of inverse model for reservoir heterogeneity characterization using parallel genetic algorithm

  • Kwon Sun-Il;Huh Dae-Gee;Lee Won-Suk;Kim Hyun-Tae;Kim Se-Joon;Sung Won-Mo
    • 한국지구물리탐사학회:학술대회논문집
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    • 2003.11a
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    • pp.719-722
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    • 2003
  • This paper presents the development of reservoir characterization model equipped with parallelized genetic algorithm, and its application for a heterogeneous reservoir system with integration of the well data and multi-phase production data. A parallel processing method performed by PC-cluster was applied to the developed model in order to reduce time for an inverse calculation. By utilizing the developed model, we performed the inverse calculation with the production data obtained from three layered reservoir system to estimate porosity and permeability distribution. As a result, the pressures observed at well almost identical to those calculated by the developed model. Also, it was confirmed that parallel processing could be applied for reservoir characterization study efficiently.

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Analysis of Genetic Relatedness in Alternaria species Producing Host Specific Toxins by PCR Polymorphism

  • Kang, Hee-Wan;Lee, Byung-Ryun;Yu, Seung-Hun
    • The Plant Pathology Journal
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    • v.19 no.5
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    • pp.221-226
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    • 2003
  • Twenty universal rice primers (URPs) were used to detect PCR polymorphisms in 25 isolates of six different Alternaria species producing host specific toxins (HST). Eight URPs could be used to reveal PCR polymorphisms of Alternaria isolates at the intra- and inter-species levels. Specific URP-PCR polymorphic bands that are different from those of the other Alternaria spp. were observed on A. gaisen and A. longipes isolates. Unweighted pair-group method with arithmetic mean (UPGMA) cluster analysis using 94 URP polymorphic bands revealed three clustered groups (A. gaisen group, A. mati complex group, and A. logipes group).

The Experimental Study on the Squeak & Rattle Noise Changes with Environment Test of Cluster (계기판의 환경 시험 후 소음 양상에 관한 시험적 연구)

  • Kim, Byung-Jim;Moon, Nam-Su;Park, Jin-Sung;Park, Hyun-Woo;Kim, Moon-Sam
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.04a
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    • pp.283-287
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    • 2012
  • Recently, Most of diverse noise of vehicles has decreased competitively according to development of the automotive manufacturing technology. Especially, Passenger car manufacturers has been conducting buzz, squeak and rattle(BSR) noise test as a method of the noise evaluation tests to reduce an unpleasant sound from interior parts on the driving the car. The purpose of this paper is to confirm the change of the noise generated in the product after the reliability evaluation. Here by the BSR test procedure used the test regulation of 'G' company.

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Metallicity, age, and alpha-element of the globular clusters in the Virgo giant elliptical galaxy NGC 4636

  • Park, Hong-Soo;Lee, Myung-Gyoon;Hwang, Ho-Seong;Arimoto, Nobuo;Yamada, Yoshihiko;Tamura, Naoyuki;Onodera, Masato
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.31.1-31.1
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    • 2010
  • We present a spectroscopic study of the globular clusters (GCs) in the giant elliptical galaxy (gE) NGC 4636 in the Virgo cluster. Line indices of GCs in NGC 4636 are measured from the integrated spectra obtained with Faint Object Camera and Spectrograph (FOCAS) on the Subaru Telescope. We derive the [Fe/H] of the GCs in NGC 4636 using Brodie & Huchra (1990) method. The [Z/H], age, and alpha-element of the GCs are obtained from the comparison of the Lick line indices with the SSP model grid. We investigate the distribution and radial variation of the metallicity, age, and alpha-element of NGC 4636 GCs. The metallicity distribution of NGC 4636 GCs shows a bimodality. The chemical properties of these GCs show little radial variation. These results will be discussed with regard to the formation and evolution of NGC 4636.

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Classification of C. elegans Behavioral Phenotypes Using Clustering (클러스터링을 이용한 C. elegans 행동표현형 분류)

  • Nah, Won;Baek, Joong-Hwan
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.1743-1746
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    • 2003
  • C. elegans often used to study of function of gene, but it is difficult for human observation to distinguish the mutants of C. elegans. To solve this problem, the system, which can be classified automatically using the computer vision, is studying now. In the previous works , they described the auto-tracking system and the egg-laying timing modeling, which are used to automated-classily system. In this paper, we use three kinds of features, which are related to movement , size and posture of the worm, and each feature is described mathematically and normalized. In experimental result, we validated the features for the hierarchical clustering, And we used the Calinski and Harabasz's method to find the appropriate cluster number.

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Surevey on the Attitudes toward Science and Science Courses of Primary and Secondary Students (초.중.고 학생의 과학 및 과학교과서에 대한 태도 조사 연구)

  • Hur, Myung
    • Journal of The Korean Association For Science Education
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    • v.13 no.3
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    • pp.334-340
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    • 1993
  • A survey on the attitudes toward science and science courses was conducted with three hundred students of primary and secondary schools. The instrument used for measuring attitudes was TOSRA(Fraser, 1981). The subjects was sampled by stratified cluster sampling method. The major findings of this study are as follows. 1. The attitude scores has no significant differences among the students of large city, mid-sized city and rural areas. 2. The attitude scores of male and female students has ststistically significant difference. 3. Primary students has significantly higher attitude scores than secondary students. 4. In case of senior high schools, science-major students has significantly higher attitude scores than humanity-major students.

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