• 대한수학회지
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• 제46권4호
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• pp.859-893
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• 2009

In this article, we will characterize structures of geometric quotient orbifolds of G-manifold of genus two where G is a finite group of orientation preserving diffeomorphisms using the idea of handlebody orbifolds. By using the characterization, we will deduce the candidates of possible non-hyperbolic geometric quotient orbifolds case by case using W. Dunbar's work. In addition, if the G-manifold is compact, closed and the quotient orbifold's geometry is hyperbolic then we can show that the fundamental group of the quotient orbifold cannot be in the class D.

• 대한수학회보
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• 제60권1호
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• pp.203-223
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• 2023

A generalized torsion element is an obstruction for a group to admit a bi-ordering. Only a few classes of hyperbolic knots are known to admit such an element in their knot groups. Among twisted torus knots, the known ones have their extra twists on two adjacent strands of torus knots. In this paper, we give several new families of hyperbolic twisted torus knots whose knot groups have generalized torsion. They have extra twists on arbitrarily large numbers of adjacent strands of torus knots.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제23권1호
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• pp.53-59
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• 2016

Let G be a finite group containing a non-abelian Sylow 2-subgroup. We elementarily show that every G-Galois field extension L/K has a hyperbolic trace form in the presence of root of unity.

• 대한수학회보
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• 제50권2호
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• pp.543-558
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• 2013

Let ${\Gamma}$ be a graph which contains two vertices $a$, $b$ with the same link. For the case where the link has less than 3 vertices, we prove that if the right-angled Artin group A(${\Gamma}$) contains a hyperbolic surface subgroup, then A(${\Gamma}$-{a}) contains a hyperbolic surface subgroup. Moreover, we also show that the same result holds with certain restrictions for the case where the link has more than or equal to 3 vertices.

• 대한수학회보
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• 제46권5호
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• pp.823-833
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• 2009

It is well-known that if a convex hyperbolic polygon is constructed as a fundamental domain for a subgroup of the modular group, then its translates by the group elements form a locally finite tessellation and its side-pairing transformations form a system of generators for the group. Such hyperbolically convex polygons can be obtained by using Dirichlet's and Ford's polygon constructions. Another method of obtaining a fundamental domain for subgroups of the modular group is through the use of a right coset decomposition and we call such domains standard fundamental domains. In this paper we give subgroups of the modular group which do not have hyperbolically convex standard fundamental domain containing only inequivalent cusps.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.457-467
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• 2010

The settlement prediction is very important to preloading method for a construction site on a soft ground. At the design stage, however, it is hard to predict the settlement exactly due to limitations of the site survey. Most of the settlement prediction is performed by a regression settlement curve based on the field data during a construction. In Korea, hyperbolic method has been most commonly used to align the settlement curve with the field data, because of its simplicity and many application cases. The results from hyperbolic method, however, may be differed by data selections or data fitting methods. In this study, the analyses using hyperbolic method were performed about the field data of $\bigcirc\bigcirc$ site in Pusan. Two data fitting methods, using an axis transformation or an alternative method, were applied with the various data group. If data was used only after the ground water level being stabilized, fitting results using both methods were in good agreement with the measured data. Without the information about the ground water level, the alternative method gives better results with the field data than the method using an axis transformation.

• 정보처리학회논문지A
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• 제8A권4호
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• pp.489-498
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• 2001

본 논문에서는 하이퍼볼릭 평면에서 임의의 분산 데이터 보간을 지역적으로 제어하는 새로운 방법을 개발하였다. 지역적 제어와 관련된 주제는 상호대화형식의 디자인분야에서 매우 중요하다. 특히 본 논문에서 제안한 방법은 하이퍼볼릭 평면상에서 형성되는 genus-N 객체 모델을 상호대화형식으로 디자인하는데 유효하게 적용될 수 있다. 특 변화된 데이터가 미치는 영향이 일정한 지역에만 국한되므로 일반 사용자가 genus-N객체를 상호대화형으로 디자인하기가 훨씬 편리하다. 따라서, 본 연구은 genus-N 객체를 형성하는데 사용한 하이퍼볼릭 평면상에서의 전역적 보간법을 발전시켜 하이퍼볼릭 평면에서의 지역적 보간법개발 및 구현을 목적으로 하고 있다. 이는 다음과 같은 주요 과정을 통하여 구현된다. 먼저, 보간 함수를 지역화하기 위하여 하이퍼볼릭 영역을 임의의 삼각형 패치로 세분화하고 각 데이터에 인접한 삼각형 패치들의 모임을 부 영역이라고 정의한다. 각 부 영역에서 가중치 함수가 설정된다. 마지막으로 중첩된 삼각형 영역의 세 개의 가중치를 혼합함으로써 지역적 보간 함수가 완성된다. 그 결과로서, 여러 개의 샘플 데이터 및 함수를 사용하여 전역적MQ 보간법과 비교한다.

• Journal of Electrical Engineering and Technology
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• 제12권2호
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• pp.926-936
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• 2017

The nonlinear behavior and the high performance requirement are the main problems that appear in the design of manipulator robots and their controllers. For that reason, the simulation, real-time execution and comparison of the performance of controllers applied to a robot with three degrees of freedom are presented. Five controllers are prepared to test the robot's dynamic model: predictive; hyperbolic sine-cosine; sliding mode; hybrid composed of a predictive + hyperbolic sine-cosine controller; and adaptive controller. A redundant robot, a communication and signal conditioning interface, and a simulator are developed by means of the MatLab/Simulink software, which allows analyzing the dynamic performance of the robot and of the designed controllers. The manipulator robot is made to follow a test trajectory which, thanks to the proposed controllers, it can do. The results of the performance of this manipulator and of its controllers, for each of the three joints, are compared by means of RMS indices, considering joint errors according to the imposed trajectory and to the controller used.

• 대한수학회논문집
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• 제13권2호
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• pp.345-358
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• 1998

Let (p/q,n) denote the orbifold with its underlying space $S^3$ and a rational knot or link p/q as its singular set with a cyclic isotropy group of order n. In this paper we shall show the geometrical realization for the case (7/3,n) for all $n \geq 3$.

• 대한수학회논문집
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• 제11권1호
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• pp.253-258
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• 1996

For a nonelementary discrete group $\Gamma$ of hyperbolic isometries acting on $B^m(m\geq2)$, we give a topological characterization of conical limit points using admissible pairs.