• ETRI Journal
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• 제11권1호
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• pp.109-122
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• 1989

We developed new quadtree and octree representation schemes which reduce the storage requirements from exponential to polynomial. The new schemes not only lessen the large storage requirements of the existing quadtree and octree representation schemes but guarantee an exact representation of the original object. These are made possible by adopting a new set of termination conditions that ensure finiteness of the quadtree and octree during the decomposition. These new data structures are analyzed theoretically and tested empirically. For space complexity, we analyzed its best case, worst case, and average case. Given an $n_e$-gon, we show that the expected number of nodes in our quadtree isO($$$n_e^1.292$) For a polyhedron with $n_f$ faces, the expected number of nodes in the new octree is O($$$n_f^1.667$). For time complexity, we again analyzed the best, worst, and average cases for constructing such quadtree and octree and find the average to be the same as those of the space complexity. Finally, random $n_e$- gons are generated as test data. Regression equations are fitted and are shown to support the claims on the average case performance.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1995년도 추계학술대회 학술발표 논문집
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• pp.307-313
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• 1995

Using the representation theorem of fuzzy number, we give the Radon-Nikodym theorem for fuzzy-number-valued measures

• 한국시뮬레이션학회논문지
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• 제6권2호
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• pp.105-115
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• 1997

Fuzzy simulation predicts the behaviors of real system based on a model by qualitative reasoning methods and simulates the representation of ambiguous values on the real system variables using the theory of fuzzy sets. During the simulation, however, unnecessary behaviors due to the fuzzy representation are created, and the number of states of system variables changing temporally in the time axis is drastically increased. In this paper, we present a new algorithm which eliminates the spurious behaviors from the great number of result values due to the results of the fuzzy operation, and reduces the number of the states by transforming the complex state transition rules. This paper also shows the easy implementation of the simulation by using the existing package while it is difficult on the PC due to the complexities of the calculation.

• 대한기계학회논문집A
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• 제20권4호
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• pp.2752-2759
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• 1996

This paper presents crack growth analysis approach on the basis of neural networks, a branch of cognitive science to high temperature low cycle fatigue that shows strong nonlinearity in material behavior. As the number of data patterns on crack growth increase, pattern classification occurs well and two point representation scheme with gradient of crack growth curve simulates crack growth rate better than one point representation scheme. Optimal number of learning data exists and excessive number of learning data increases estimated mean error with remarkable learning time J-da/dt relation predicted by neural networks shows that test condition with unlearned data is simulated well within estimated mean error(5%).

• 한국수학교육학회:학술대회논문집
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• 한국수학교육학회 1990년도 전국수학교육연구대회
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• pp.65-65
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• 1990

• 대한수학회지
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• 제41권6호
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• pp.945-955
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• 2004

In this paper, we establish a number system in $R^n$ which arises from a Haar wavelet basis in connection with decompositions of certain Cuntz algebra representations on $L^2$( $R^n$). Number systems in $R^n$ are also of independent interest [9]. We study radix-representations of $\chi$ $\in$ $R^n$: $\chi$:$\alpha$$_{ι}$ $\alpha$$_{ι-1}$…$\alpha$$_1$$\alpha$$_{0}$ ㆍ$\alpha$$_{-1}$ $\alpha$$_{-2}$ … as $\chi$= $M^{ι}$$\alpha$$_{ι}$ $\alpha$＋…M$\alpha$$_1$＋$\alpha$$_{0}$ ＋ $M^{-1}$ $\alpha$$_{-1}$ ＋ $M^{-2}$ $\alpha$$_{-2}$ ＋… where each $\alpha$$_{k}$ $\in$ D, and D is some specified digit set. Our analysis uses iteration techniques of a number-theoretic flavor. The view-point is a dual one which we term fractals in the large vs. fractals in the small,illustrating the number theory of integral lattice points vs. fractions.s vs. fractions.

• 정보처리학회논문지D
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• 제12D권2호
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• pp.327-334
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• 2005

복잡한 구조의 웹사이트를 표현하기 위해 EMG(Extended Mark Flow Graph)를 이용한 웹사이트의 표현이 연구되고 있다. 대부분의 웹사이트들은 반복구조가 많이 나타나고, 이러한 웹사이트들을 EMFG로 표현하면 너무 복잡하여 때로는 웹사이트의 구조의 파악이 어려워지게 된다. 따라서 본 논문에서는 웹사이트를 EMG로 표현할 때 나타나는 반복구조를 직렬반복구조와 병렬반복구조로 분류하고, 이를 간략화하여 박스, 아크, 트랜지션의 수를 줄여 전체 웹사이트의 구조 및 웹페이지 간의 이동관계를 효율적으로 설계하고 관리할 수 있는 방법을 제시하고자 한다.

• 한국정보처리학회논문지
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• 제6권3호
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• pp.781-791
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• 1999

DD(Decision Diagrams) is an efficient operational data structure for an optimal expression of boolean functions. In a graph-based synthesis using DD, the goal of optimization decreases representation space for boolean functions. This paper represents boolean functions using OPKFDD(Ordered Pseudo-Kronecker Functional Decision Diagrams) for a graph-based synthesis and is based on the number of nodes as the criterion of DD size. For a property of OPKFDD that is able to select one of different decomposition types for each node, OPKFDD is variable in its size by the decomposition types selection of each node and input variable order. This paper proposes a method for generating OPKFDD efficiently from the current BDD(Binary Decision Diagram) Data structure and an algorithm for minimizing one. In the multiple output functions, the relations of each function affect the number of nodes of OPKFDD. Therefore this paper proposes a method to decide the input variable order considering the above cases. Experimental results of comparing with the current representation methods and the reordering methods for deciding input variable order are shown.

• 융합신호처리학회논문지
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• 제9권1호
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• pp.54-61
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• 2008

본 논문에서는 디지털 신호를 실시간으로 처리하기 인한 TIQ 방식의 Flash 6-bit ADC 회로를 설계하였다. 새로운 논리회로 설계나 소자들의 근접 배치로 ADC의 속도를 향상시키는 대신에 새로운 코드를 이용하여 DSP의 처리능력을 높이도록 하였다. 제안한 코드는 ADC의 출력으로 이진수를 세공하지 않고 2와 3진법을 동시에 사용하는 Double Base Number System(DBNS)방법이다. 전압은 기존의 이진수를 표시하는 방법과 동일하지만, 밑수로 2와 3의 두개를 동시에 사용하여 합의 형태로 표현하는 방법이다. DBNS 표현법은 곱셈기와 가산기를 이용하지 않고 연산을 좌우로 이동하여 연산을 신속히 처리할 수 있다. 디지털 신호처리에서 사용하는 DBNS는 합의 수가 적도록 Canonical 표현을 구하는 알고리즘을 사용하지만, A/D 변환기에서는 Fan-In 문제가 발생하여 균일한 분포를 이루도록 하는 새로운 알고리즘을 개발하였다. HSPICE를 이용한 ADC의 시뮬레이션 결과 0.18um 공정에서 최고 동작속도는 1.6 GSPS이며 최대 소비전력은 38.71mW이였다.

• 한국수학교육학회지시리즈A:수학교육
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• 제56권2호
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• pp.131-145
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• 2017

The representation of irrational numbers has a key role in the learning of irrational numbers. However, transparent and finite representation of irrational numbers does not exist in school mathematics context. Therefore, many students have difficulties in understanding irrational numbers as an 'Object'. For this reason, this research explored how mathematics textbooks affected to students' understanding of irrational numbers in the view of process and object. Specifically we analyzed eight textbooks based on current curriculum and used framework based on previous research. In order to supplement the result derived from textbook analysis, we conducted questionnaires on 42 middle school students. The questions in the questionnaires were related to the representation and calculation of irrational numbers. As a result of this study, we found that mathematics textbooks develop contents in order of process-object, and using 'non repeating decimal', 'numbers cannot be represented as a quotient', 'numbers with the radical sign', 'number line' representation for irrational numbers. Students usually used a representation of non-repeating decimal, although, they used a representation of numbers with the radical sign when they operate irrational numbers. Consequently, we found that mathematics textbooks affect students to understand irrational numbers as a non-repeating irrational numbers, but mathematics textbooks have a limitation to conduce understanding of irrational numbers as an object.