• 한국공간정보시스템학회 논문지
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• 제11권4호
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• pp.39-46
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• 2009

일반적으로 휴리스틱을 이용한 알고리즘에서는 탐색 비용이 증가하는 문제가 발생할 수 있다. 휴리스틱에 의해 결정된 추정 경로에 실제 경로가 존재하지 않을 경우, 휴리스틱 가중치 값이 비슷한 2 가지 이상의 경로가 존재할 경우 탐색 비용이 증가한다. 이 논문에서는 탐색 비용 증가 문제점을 해결하기 위해 추상 그래프를 제안한다. 추상 그래프는 실제 도로를 단순화한 그래프로서, 전체 지도를 고정된 크기의 그리드 셀로 나누고, 셀과 도로 정보를 기반으로 생성된다. 경로 탐색은 추상 그래프 탐색, 실제 도로 네트워크 탐색 순으로 2단계로 수행된다. 106,254개의 간선으로 이루어진 실제 도로 네트워크 데이터에 대해서 성능 평가 실험을 수행한 결과와 탐색 비용 측면에서 그리드 셀 크기에 따라 그리드 기반 A* 알고리즘에 비해 최소 3%에서 최대 35% 좋은 성능을 보였다. 반면에 유효 셀을 제외한 영역에 대한 탐색이 이루어지지 않기 때문에, 생성된 경로의 이동 비용은 1.5~6.6% 증가하였다.

• 호남수학학술지
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• 제37권3호
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• pp.361-376
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• 2015

We have calculated the volume of the graph polytopes associated with several types of graphs.

• 한국수학교육학회지시리즈A:수학교육
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• 제13권2호
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• pp.6-10
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• 1974

We consider 'ordinary' graphs: that is, finite undirected graphs with no loops or multiple edges. An intersection representation of a graph G is a function r from V(G), the set of vertices of G, into a family of sets S such that distinct points $\chi$$_{\alpha}$ and $\chi$$_{\beta}$/ of V(G) are. neighbors in G precisely when ${\gamma}$($\chi$$_{\alpha}$)∩${\gamma}$($\chi$$_{\beta}$/)$\neq$ø, A graph G is a rigid circuit grouph if every cycle in G has at least one triangular chord in G. In this paper we consider the main theorem; A graph G has an intersection representation by arcs on an acyclic graph if and only if is a normal rigid circuit graph.uit graph.d circuit graph.uit graph.

• International Journal of Contents
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• 제10권1호
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• pp.23-28
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• 2014

When developing a classifier using various objective functions, it is important to compare the performances of the classifiers. Although there are statistical analyses of objective functions for classifiers, simulation results can provide us with direct comparison results and in this case, a comparison criterion is considerably critical. A Receiver Operating Characteristics (ROC) graph is a simulation technique for comparing classifiers and selecting a better one based on a performance. In this paper, we adopt the ROC graph to compare classifiers trained by mean-squared error, cross-entropy error, classification figure of merit, and the n-th order extension of cross-entropy error functions. After the training of feed-forward neural networks using the CEDAR database, the ROC graphs are plotted to help us identify which objective function is better.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 제13회 신호처리 합동 학술대회 논문집
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• pp.671-674
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• 2000

In this paper, we present a robust global registration algorithm for multi-frame image mosaics. When we perform a pair-wise registration recovering a projective transformation between two consecutive frames, severe mis-registration among multiple frames, which are not consecutive, can be detected. It is because the concatenation of those pair-wise transformations leads to global alignment errors. To overcome those mis-registrations, we propose a new algorithm using multiple frames for constructing image mosaics. We use a graph to represent the temporal and spatial connectivity and show that global registration can be obtained through the search for an optimal path in the constructed graph. The definition of an adequate objective function characterizing the global registration provides a direct manipulation of the graph. In the presence of moving objects, especially large ones compared with low texture backgrounds, by using the likelihood ratio as the objective function, we can deal with some of the most challenging videos like basketball or soccer Moreover, the algorithm can be parallelized so it can be more efficiently implemented. Finally, we give some experimental results from real videos.

• 대한수학회보
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• 제59권5호
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• pp.1305-1315
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• 2022

Let u be a function on a connected finite graph G = (V, E). We consider the mean field equation (1) $-{\Delta}u={\rho}\({\frac{he^u}{\int_Vhe^ud{\mu}}}-{\frac{1}{{\mid}V{\mid}}}\),$ where ∆ is 𝜇-Laplacian on the graph, 𝜌 ∈ ℝ\{0}, h : V → ℝ⁺ is a function satisfying min_x∈V h(x) > 0. Following Sun and Wang [15], we use the method of Brouwer degree to prove the existence of solutions to the mean field equation (1). Firstly, we prove the compactness result and conclude that every solution to the equation (1) is uniformly bounded. Then the Brouwer degree can be well defined. Secondly, we calculate the Brouwer degree for the equation (1), say $$d_{{\rho},h}=\{{-1,\;{\rho}>0, \atop 1,\;{\rho}<0.}$$ Consequently, the equation (1) has at least one solution due to the Brouwer degree d_𝜌,h ≠ 0.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권5호
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• pp.2084-2100
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• 2020

Operating system (OS) kernel function call graphs have been widely used in OS analysis and defense. However, most existing methods and tools for generating function call graphs are designed for application programs, and cannot be used for generating OS kernel function call graphs. This paper proposes a virtualization-based call graph generation method called Acquire in Trap (AIT). When target kernel functions are called, AIT dynamically initiates a system trap with the help of a virtualization technique. It then analyzes and records the calling relationships for trap handling by traversing the kernel stacks and the code space. Our experimental results show that the proposed method is feasible for both Linux and Windows OSs, including 32 and 64-bit versions, with high recall and precision rates. AIT is independent of the source code, compiler and OS kernel architecture, and is a universal method for generating OS kernel function call graphs.

• 대한수학회지
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• 제43권6호
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• pp.1301-1324
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• 2006

The affine homogeneous hypersurface in ${\mathbb{R}}^{n+1}$, which is a graph of a function $F:{\mathbb{R}}^n{\rightarrow}{\mathbb{R}}$ with |det DdF|=1, corresponds to a complete unimodular left symmetric algebra with a nondegenerate Hessian type inner product. We will investigate the condition for the domain over the homogeneous hypersurface to be homogeneous through an extension of the complete unimodular left symmetric algebra, which is called the graph extension.

• Journal of applied mathematics & informatics
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• 제39권1_2호
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• pp.223-237
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• 2021

Let G = (V (G), E(G)) be a graph and let g : V (G) → S3 be a function. For each edge xy assign the label r where r is the remainder when o(g(x)) is divided by o(g(y)) or o(g(y)) is divided by o(g(x)) according as o(g(x)) ≥ o(g(y)) or o(g(y)) ≥ o(g(x)). The function g is called a group S3 cordial remainder labeling of G if |vg(i)-vg(j)| ≤ 1 and |eg(1)-eg(0)| ≤ 1, where vg(j) denotes the number of vertices labeled with j and eg(i) denotes the number of edges labeled with i (i = 0, 1). A graph G which admits a group S3 cordial remainder labeling is called a group S3 cordial remainder graph. In this paper, we prove that square of the path, duplication of a vertex by a new edge in path and cycle graphs, duplication of an edge by a new vertex in path and cycle graphs and total graph of cycle and path graphs admit a group S3 cordial remainder labeling.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제22권2호
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• pp.125-136
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• 2008

동일한 함수 그래프를 접근하는 방법은 다양하다. 물리 교과에서는 중력상태에서 물체의 운동으로 포물선을 정의하고 있으며 수학 교과에서는 수식을 이용한 이차함수로 포물선을 정의한다 본 연구에서는 교육과정에 나타나는 함수 그래프를 국소적이며 내재적인 거북 행동의 관점에서 접근하고 분석한다. 또한 교육과정에 나타나지 않지만 수학사에서 중요한 의미를 가지는 몇몇 곡선에 대하여 같은 방법으로 곡선을 구성하고자 한다. 그리고 pre-calculus의 관점에서 고등학생의 지식을 바탕으로 곡선의 길이와 넓이를 구하는 수학화 활동을 소개한다.