• The Mathematical Education
• /
• v.58 no.3
• /
• pp.403-422
• /
• 2019

As the informal graph was introduced newly in the area of function in middle school mathematics curriculum revised in 2015, ten publishing company became to have a concern on how to represent the graph content uniquely and newly. At this time, it may be meaningful and useful to compare and analyze the content of the graph unit shown on each textbook published by publishing companies. To accomplish this, on fundamentally the basis of diverse prior researches this study tried to select the elements of expression and interpretation of the graph and establish an analytic frameworks of expression and interpretation of the graph respectively. This study executed the frequency analysis and cross analysis by textbook system, textbook, and the number of the graph drawn on a coordinate plane on the representation and interpretation of the graph. As a result, the textbook contains more items on interpretation than the representation of the graph, and students showed a learning effect on the graph unit but showed a neutral response to the impact of learning. This basic and essential paper shed light on developing the practical and more creative textbook which has diversity and characteristic respectively, while adjusting the scope of the elements of the graph's representations and interpretations and providing proper level and quality content.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.932-933
• /
• 2008

본 논문에서는 매트릭스 컨버터의 두가지 전압 변조 방법을 직관적이고 직접적인 그래픽적 접근을 통해 비교 분석한다. 전압 변조에 있어서 옵셋전압 PWM방법은 캐리어비교를 기본으로 하여 옵셋전압을 더함으로써 전압 변조를 하고, $V_{max}-V_{mid}$ PWM 방법은 샘플링 주기내에서 한상을 고정시키고 나머지 두 상을 온-오프 하는 방식으로 전압 변조를 한다. 이 과정에서 중요한 두가지 특징이 전류 리플과 스위칭 손실이고, 전류 리플과 관련해서 각변조 방법의 고조파 전압을 그래프로 그려 분석한다.먼저 출력지령전압 벡터와 각 스위칭 영역별 벡터간의 차에 의한 고조파 성분을 스위칭 한주기내에서 벡터도를 그리고, 그 다음으로 출력전압 위상각과 전압 변조율을 달리 하여 각각의 고조파 전압 그래프를 그려 비교 분석해 보았다.

• Journal of KIISE:Software and Applications
• /
• v.32 no.4
• /
• pp.290-299
• /
• 2005

Stealing the source code of a program is a serious problem not only in a moral sense but also in a legal sense. However, it is not clear whether the code of a program is copied from another or not. There was a program similarity checker detecting code-copy by comparing the syntax trees of programs. However this method has a limitation that it cannot detect the code-copy attacks when the attacker modifies the syntax of the program on purpose. We propose a program similarity check by program control graph, which reveals not only syntax information but also control dependancy. Our method can detect the code-copy attacks that do not change control dependancy Moreover, we define what code-copy means and establish the connection between code-copy and similarity of program control graph: we prove that two programs are related by copy congruence if and only if the program control graphs of these programs are equivalent. We implemented our method on a functional programming language, nML. The experimental results show us that the suggested method can detect code similarity that is not detected by the existing method.

• Journal of Digital Convergence
• /
• v.19 no.10
• /
• pp.403-410
• /
• 2021

Given an undirected simple graph, k-club is one of the proposed structures to model social groups that exist in various types in Social Network Analysis (SNA). Maximum k-Club Problem (MkCP) is to find a k-club of maximum cardinality in a graph. This paper introduces a Genetic Algorithm called HGA+DROP which can be used to approximate maximum k-club in graphs. Our algorithm modifies the existing k-CLIQUE & DROP algorithm and utilizes Heuristic Genetic Algorithms (HGA) to obtain multiple k-clubs. We experiment on DIMACS graphs for k = 2, 3, 4 and 5 to compare the performance of the proposed algorithm with existing algorithms.

• Applied Biological Chemistry
• /
• v.41 no.6
• /
• pp.421-425
• /
• 1998

The amylograph pasting properties of flours $(9{\sim}12%,\;db)$ and starches $(7.5{\sim}9.0%\;db)$ of Korean rice cultivars indicated that the flour concentration to give a fixed peak viscosity was higher by 1.32 times compared with starch, regardless the maturity. Only at 12% flour concentration the peak viscosity and breakdown viscosity were differentiated among maturity groups, which suggested that flour may be better tool than starch in characterizing the maturity groups by pasting properties.

• Composites Research
• /
• v.30 no.3
• /
• pp.193-201
• /
• 2017

Molecular dynamics simulation and the Mori-Tanaka micromechanics study are performed to investigate the effect of the covalent grafting between CNT and polyester on the mechanical behavior and load transfer of nanocomposites. The transversely isotropic stress-strain curves are determined through the tension and shear simulations according to the covalent grafting. Also, isotropic properties of randomly dispersed nanocomposites are obtained by orientation averaging the transversely isotropic stiffness matrix. By addressing the grafting, the transverse Young's modulus and shear moduli of the nanocomposites are improved, while the longitudinal Young's modulus decreases due to the degradation of the grafted CNT.

• Journal of the Korean Society for information Management
• /
• v.13 no.1
• /
• pp.205-226
• /
• 1996

Under the hypothesis that any pair of terms in the sentence is meaningful to present the context of the paper, the Brillouin measure of term relatedness in automatic indexing is proposed. For the experiment, the pair of terms simul-taneously appeared in two or more sentences of the paper are extracted from the title and abstract of the paper. Com-pared with the list of index terms or subject headings suggested by the author, the terms in term relatedness graph are highly matched with the terms in the list. Especially, it is revealed that the rank of terms by synthetic strength is use-ful in the selection of index terms.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.04a
• /
• pp.469-472
• /
• 2012

최근 IT 분야의 화두로 '빅 데이터'가 떠오르고 있으며 많은 기업들이 이를 분석하여 이익을 증대하기 위한 노력을 하고 있다. 이에 구글은 초기에 맴리듀스라고 하는 대용량 분산처리 프레임워크 기술을 확보하여 이를 기반으로 한 서비스를 제공하고 있다. 그러나 스마트 단말 및 소설미디어 등의 출현으로 다양한 디지털 정보들이 그래프로 표현되는 추세가 강화되고 있으며 기존의 맵리듀스로 이를 처리하는 데에 한계를 느낀 구글은 Pregel 이라는 그래프 형 자료구조에 최적화된 또 다른 분산 프레임워크를 개발하였다. 본 논문에서는 일반적인 그래프 형 데이터가 갖는 특성을 분석하고, 대용량 그래프 데이터를 처리하는데 있어 맵리듀스가 갖는 한계와 Pregel은 어떤 방식으로 이를 극복하고 있는지를 소개한다. 또한 실험을 통하여 데이터의 특성에 따른 적절한 프레임워크의 선택이 대용량 데이터를 처리하는 데에 있어서 얼마나 큰 영향을 미치는지 확인한다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.17 no.2
• /
• pp.367-374
• /
• 2022

A sampling set selection algorithm is proposed to reconstruct original graph signals from the sampled signals generated on the nodes in the sampling set. Instead of directly minimizing the reconstruction error, we focus on minimizing the upper bound on the reconstruction error to reduce the algorithm complexity. The metric is manipulated by using QR factorization to produce the upper triangular matrix and the analytic result is presented to enable a greedy selection of the next nodes at iterations by using the diagonal entries of the upper triangular matrix, leading to an efficient sampling process with reduced complexity. We run experiments for various graphs to demonstrate a competitive reconstruction performance of the proposed algorithm while offering the execution time about 3.5 times faster than one of the previous selection methods.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.13 no.4
• /
• pp.107-116
• /
• 2013

This algorithm suggests a method in which a minimum spanning tree can be obtained fast by reducing the number of an algorithm execution. The suggested algorithm performs a select-and-delete process. In the select process, firstly, it performs Borůvka's first stage for all the vertices of a graph. Then it re-performs Borůvka's first stage for specific vertices and reduces the population of the edges. In the delete process, it deletes the maximum weight edge if any cycle occurs between the 3 edges of the edges with the reduced population. After, among the remaining edges, applying the valency concept, it gets rid of maximum weight edges. Finally, it eliminates the maximum weight edges if a cycle happens among the vertices with a big valency. The select-and-delete algorithm was applied to 9 various graphs and was evaluated its applicability. The suggested select process is believed to be the vest way to choose the edges, since it showed that it chose less number of big edges from 6 graphs, and only from 3 graphs, comparing to the number of edges that is to be performed when using MST algorithm. When applied the delete process to Kruskal algorithm, the number of performances by Kruskal was less in 6 graphs, but 1 more in each 3 graph. Also, when using the suggested delete process, 1 graph performed only the 1st stage, 5 graphs till 2nd stage, and the remaining till 3rd stage. Finally, the select-and-delete algorithm showed its least number of performances among the MST algorithms.