• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.180-185
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• 2003

In order to enhance dexterity in execution of robot tasks, a redundant number of degrees-of-freedom (DOF) is adopted for design of robotic mechanisms like robot arms and multi-fingered robot hands. Associated with such redundancy in the number of DOFs relative to the number of physical variables necessary and sufficient for description of a given task, an extra performance index is introduced for controlling such a redundant robot in order to avoid arising of an ill-posed problem of inverse kinematics from the task space to the joint space. This paper shows that such an ill-posedness of DOF redundancy can be resolved in a natural way by using a novel concept named “stability on a manifold”. To show this, two illustrative robot tasks 1) robotic handwriting and 2) control of an object posture via rolling contact by a multi-DOF finger are analyzed in details.

• Journal of ILASS-Korea
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• v.2 no.4
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• pp.36-46
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• 1997

The present study investigated the effects of MTV(Manifold Throttle Valve) on the fuel distribution and the flame stability in a SI engine at cold, idling condition. For the quantitative measurement of fuel distribution with PLIF method, compensating techniques of various factors such as laser beam nonuniformity, background image and local OTF nonuniformity were developed. As a result, it was found that MTV had a positive effect on the air-fuel mixing and flame stability.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.6-8
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• 1994

In this paper an attempt is made to understand the voltage stability when the power system networks are represented by the differential-algebraic equations (DAEs) form. The problem is analyzed by interpreting the shape of constraint manifold, based on the singular perturbation model. The global picture or constraint manifold is given to show how the local shape or constraint manifold can be used to guess for the system behavior. The gradient analysis is used systematically to obtain a local shape or the constraint manifold.

• Honam Mathematical Journal
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• v.32 no.1
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• pp.167-176
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• 2010

Let (B, $\check{g}$) and (N, $\hat{g}$) be Einstein manifolds. Then, we get a complete (necessary and sufficient) condition for the warped product manifold $B\;{\times}_f\;N\;:=\;(B\;{\times}\;N,\;\check{g}\;+\;f{\hat{g}}$) to be Einstein, and obtain a complete condition for the Einstein warped product manifold $B\;{\times}_f\;N$ to be weakly stable. Moreover, we get a complete condition for the map i : ($B,\;\check{g})\;{\times}\;(N,\;\hat{g})\;{\rightarrow}\;B\;{\times}_f\;N$, which is the identity map as a map, to be harmonic. Under the assumption that i is harmonic, we obtain a complete condition for $B\;{\times}_f\;N$ to be Einstein.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.5912-5918
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• 2014

Owing to highly developed industries and the use of fossil fuels, environmental problems becoming becoming pressing issues globally. Therefore, a study of automobile exhaust is urgently needed. Generally, air is sucked into the engine through the intake manifold. The aims of this study were to reduce the exhaust from used cars and increase the output by removing carbon deposits, which are considered a reason for the increasing exhaust and reduction of output, and the reduction of exhaust, variation of output and stability of idle speed were analyzed. The formation of carbon deposits within the suction manifold was investigated through a test device (KD147). In the intake manifold, the exhaust cleaning effect was confirmed.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.3
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• pp.22-30
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• 2011

There is a many way of LPRE throttling methods, high-pressure-drop systems, dual-manifold injector, gas injection, multiple chambers, pulse modulation and movable injector components. Especially dual-manifold injector is essentially combines two fixed-area injectors into a common structure, with independent feed systems controlling flow to each injector manifold. In this paper, using indirect photography and liquid film thickness measurement with various injection pressure and tangential entry diameter to decide stability of spray over a wide thrust range in dual manifold injector.

• Bulletin of the Korean Mathematical Society
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• v.26 no.2
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• pp.175-177
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• 1989

The following is the basic problem about the stability in Riemannian Geometry; given a Riemannian manifold N, find all stable complete minimal submanifolds of N. As answers of this problem, do Carmo-Peng [1] and Fischer-Colbrie and Schoen [3] showed that the stable minimal surfaces in R$^{3}$ are planes and Schoen-Yau [5] and Fischer-Colbrie and Schoen [3] gave a solution for the case where the ambient space is a three dimensional manifold with nonnegative scalar curvature. In this paper we will remove the assumption of finite absolute total curvature in [3, Theorem 3].

• Journal of the Chungcheong Mathematical Society
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• v.13 no.1
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• pp.53-63
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• 2000

The inverse shadowing property of a dynamical system is an "inverse" form of the shadowing property of the system. Recently, Kloeden and Ombach proved that if an expansive system on a compact manifold has the shadowing property then it has the inverse shadowing property. In this paper, we study topological stability of the inverse shadowing dynamical systems. In particular, we show that if an expansive system on a compact manifold has the inverse shadowing property then it is topologically stable, and so it has the shadowing property.

• Kyungpook Mathematical Journal
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• v.58 no.3
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• pp.559-571
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• 2018

In this paper, we give some results on the stability of f-harmonic maps with potential from or into spheres and any Riemannian manifold. We study the constant boundary-value problems of such maps defined on a specific Cartan-Hadamard manifolds, and obtain a Liouville-type theorem. It can also be applied to the static Landau-Lifshitz equations. We also prove a Liouville theorem for f-harmonic maps with finite f-energy or slowly divergent f-energy.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.2
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• pp.295-307
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• 1988

In order to predict performance of the intake manifold, which is dependent on the length and diameter of a resonance pipe, the Fluid Dynamic Model for 4-cylinder diesel engine is developed using two step Lax-Wendroff method to solve the governing equations of air flow in the intake system. Boundary conditions at the intake valve, branch at the manifolds, and pipe end are also modeled. The results of the models are compared with the experimental results of a motored engine. The model is capable of predicting the real phenomena satisfactorily with reasonable computing time.