• Communications of the Korean Mathematical Society
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• v.32 no.1
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• pp.85-92
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• 2017

We give expressions of a biquaternion and research operations and calculations of each form of a biquaternion. Also, we investigate representations and properties of exponential and trigonometric forms of a biquaternion.

• Communications of the Korean Mathematical Society
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• v.10 no.1
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• pp.137-143
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• 1995

First we recall some properties of the spaces $D_p$ and study the continuity of the operators on $D_p$. We also consider the continuity of the operations on the dual spaces $D'_p$ with the weak topology.

• Communications for Statistical Applications and Methods
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• v.3 no.3
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• pp.235-245
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• 1996

In this paper, a partial ordering of positive quadrant dependence(PQD) for bivariate stochastic processes are introduced and basic properties and closure under certain statistical operations are derived. Examples are given to illustrate these concepts

• Korean Journal of Mathematics
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• v.23 no.4
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• pp.557-569
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• 2015

We dene a fuzzy lattice as a fuzzy relation, develop some basic properties of the fuzzy lattice, show that the operations of join and meet in fuzzy lattices are isotone and associative, characterize a fuzzy lattice by its level set, and show that the direct product of two fuzzy lattices is a fuzzy lattice.

• Korean Management Science Review
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• v.14 no.2
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• pp.63-68
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• 1997

Limiting probability in the steady state of regenerative process is one of the most useful characteristics. The formula for this limiting probability in the steady state of the regenerative process is presented in this paper. Because this formula is for the general model, it can be applied to many special systems including 2-unit redundant system. An example for this formula is also presented.

• Korean Management Science Review
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• v.11 no.1
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• pp.107-115
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• 1994

Stochastic manufacturing systems are generally formulated as performance models of discrete event systems. In this paper, logical models(as opposed to performance models) of kanban systems are presented which are deterministic and untimed but not stochastic and timed. As a result, the first and second order properties of kanban systems are showed which can be fruitfully applied to the analysis and design of kanban systems.

• Korean Journal of Mathematics
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• v.16 no.3
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• pp.403-412
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• 2008

We define the operations ${\vee}$ and ${\wedge}$ for fuzzy sets in a lattice, characterize fuzzy sublattices in terms of ${\vee}$ and ${\wedge}$, develop some properties of the distributive fuzzy sublattices, and find the fuzzy ideal generated by a fuzzy subset in a lattice and the fuzzy dual ideal generated by a fuzzy subset in a lattice.

• The Journal of Korean Association of Computer Education
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• v.9 no.1
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• pp.89-95
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• 2006

The local geometric properties such as curvatures and normal vectors play important roles for analyzing the local shape of objects in the fields of computer graphics and computer vision. The result of the geometric operations such as mesh simplification and mesh smoothing is dependent on how to compute the curvatures of meshes because there is no exact mathematical definition of curvature at vertices on 3D meshes. Therefore, In this paper, we indicate the fatal error in computing the sectional curvatures of the most previous discrete curvature estimations. Moreover, we present a discrete curvature estimation to overcome the error, which is based on the parabola interpolation and the geometric properties of Bezier curves. Therefore, We can well distinguish between the sharp vertices and the flat ones, so our method may be applied to a variety of geometric operations.

• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.5
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• pp.621-626
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• 2003

In this paper, we modeled a virtual life (VL) that reacts to the user s action according to its own behavioral characteristics and grows itself. We established some conditions with which such a VL is designed. Genetic Algorithm is used for the growth process that changes the VL s properties. In this process, the parameter values of the VL s properties are encoded as one chromosome, and the GA operations change this chromosome. The VL s reaction to the user s action is determined by these properties as well as the general expectation of each reaction. These properties are evaluated through 5 fitness measures so as to deal with multi-objective criteria. Here, we present the simulation of the growth Process, and show some experimental results.

• Communications of the Korean Mathematical Society
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• v.27 no.1
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• pp.7-13
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• 2012

In this paper we consider pseudo-BCK/BCI-algebras. In particular, we consider properties of minimal elements ($x{\leq}a$ implies x = a) in terms of the binary relation $\leq$ which is reflexive and anti-symmetric along with several more complicated conditions. Some of the properties of minimal elements obtained bear resemblance to properties of B-algebras in case the algebraic operations $\ast$ and $\circ$ are identical, including the property $0{\circ}(0{\ast}a)$ = a. The condition $0{\ast}(0{\circ}x)=0{\circ}(0{\ast}x)=x$ all $x{\in}X$ defines the class of p-semisimple pseudo-BCK/BCI-algebras($0{\leq}x$ implies x = 0) as an interesting subclass whose further properties are also investigated below.