• Journal of Mechanical Science and Technology
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• v.17 no.10
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• pp.1466-1474
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• 2003

This paper presents a system modeling, controller design and implementation for a rotational inverted pendulum system (RIPS), which is an under-actuated system and has the problem of unattainable velocity state. Two control strategies are applied to the RIPS. One is a sliding mode control method using the parameterization of both the hyperplane and the compensator for output feedback. The other is the disturbance observer which estimates disturbance and some modeling errors of RIPS with less computational effort. Some simulations and various kinds of experiments are performed in order to verify that the proposed controller has the ability to control RIPS whose velocity is assumed to be unavailable. The results of the simulations and experiments show that the proposed control system has superior performance for disturbance rejection and regulation at certain initial conditions as well as the robustness to model uncertainties.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.76-79
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• 1988

The sliding mode control in an effective method to eatablish robustness against parameter variation and disturbance. But. In sliding mode strategy, the control function is discontinuous on the hyperplane. However the discontinuous change in control structure caves the controller input to chaffer and gives non-zero steady state error. Consequently, a multiloop feedback control system supplemented by a complelmentary controller is used to improved the drive performence of a DC servo motor and reduce sensitivity to parameter variation, nonlinear effects, and other disturbances.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11a
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• pp.301-304
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• 2003

SVM은 일반화된 높은 분류 정확률을 보인다. 그러나, SVM은 데이터의 양이 커질수록 높은 시간 공간적 복잡성 때문에 근사화 알고리즘(Approximation Algorithm)을 이용한다. 이러한 접근 방법은 실제구현에서 높은 시간 공간적 복잡성을 요구하여 분류 정확률과 효율성을 낮아지게 한다. 따라서, 본 논문은 SVM을 앙상블 구조로 구성하여 분류 정확률을 높이고, 분류자의 최적 하이퍼플랜(Optimal Hyperplane)결정을 위해 마진 벡터만을 이용하여 시간 공간적 문제를 해결하였다. 실험결과, 본 논문에서 제시한 방법이 단일 SVM을 이용한 방법보다 높은 분류 정확률과 높은 효율성을 가짐을 보여준다...

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.405-407
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• 2009

SVM(Support Vector Machine) is a classification method which is recently watched in mechanical learning system. Vapnik, Osuna, Platt etc. had suggested methodology in order to solve needed QP(Quadratic Programming) to realize SVM so that have extended application field. SVM find hyperplane which classify into 2 class by converting from input space converter vector to characteristic space vector using Kernel Function. This is very systematic and theoretical more than neural network which is experiential study method. Although SVM has superior generalization characteristic, it depends on Kernel Function. There are three category in the Kernel Function as Polynomial Kernel, RBF(Radial Basis Function) Kernel, Sigmoid Kernel. This paper has analyzed performance of SVM against kernel using virtual data.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.166-176
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• 1994

본 논문에서는 'back propagation' 신경망 알고리즘을 이용하여 자동 신용 평가 시스템을 개발하고 실제 데이타를 이용하여 이 시스템을 평가하여 보았다. 평가 과정중 신경망의 학습 수렴속도와 그의 여부는 학습에 이용된 데이타의 수에 따라 민감하게 변화한다는 것과 학습후 학습에 이용되지 않은 새로운 데이타들에 대한 신용 평가의 판별력과 학습에 이용된 데이타들에 대한 신용 평가의 판별력 사이에는 유의한 차이가 있음도 관찰되었다. 그리고, 학습에 이용된 데이타들의 갯수가 임의의 한 경계점을 넘어서면, 기존의 다른 많은 연구들이 주장했던 것과는 달리 학습 수렴 여부와 판별력이 급격히 떨어진다는 것도 관찰되었다. 또한 본 논문에서는 이상에서와 같이 관찰된 시스템 평가 결과를 신경망 이론의 학습 방법과 error space상에서 hyperplanes이 작용하는 역할의 관점에서 해석하였다.

• Honam Mathematical Journal
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• v.35 no.1
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• pp.37-49
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• 2013

Consider a non-degenerate open convex cone C with vertex the origin in the $n$2-dimensional Euclidean space $E^n$. We study volume properties of strictly convex hypersurfaces in the cone C. As a result, for example, if the volume of the region of an elliptic cone C cut off by the tangent hyperplane P of M at $p$ is independent of the point $p{\in}M$, then it is shown that the hypersurface M is part of an elliptic hyperboloid.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.365-372
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• 2006

A new meshfree formulation is developed for material discontinuity problems. A local interfacial jump function which is defined as hyperplane function is embedded in the meshless approximation and the approximation accurately models functions with jumps in the displacement and the derivative fields. Diffuse derivative technique copes with difficulty due to complexity of derivative computation of meshfree approximation. Collocation method with diffuse derivative accelerates computing speed for numerical solution. By solving inclusion and composite material problems, the robustness and effectiveness of the method are verified.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.7
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• pp.2480-2495
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• 2014

This paper describes a hierarchical method for image-based age estimation that combines age group classification and age value estimation. The proposed method uses a coarse-to-fine strategy with different appearance features to describe facial shape and texture. Considering the damage to continuity between neighboring groups caused by fixed divisions during age group classification, a dynamic grouping technique is employed to allow non-fixed groups. Based on the given group, an ordinal hyperplane ranking (OHRank) model is employed to transform age estimation into a series of binary enquiry problems that can take advantage of the intrinsic correlation and ordinal information of age. A set of experiments on FG-NET are presented and the results demonstrate the validity of our solution.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.249-254
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• 1998

A control approach for the robust position control of induction motors based on the improved binary disturbance observer is described. The conventional binary disturbance observer is used to remove the chattering problem of a sliding mode disturbance observer. However, the steady state error may be existed in the conventional binary disturbance observer because it estimates external disturbance with a constant boundary layer. In order to overcome this problem, a new binary disturbance observer with an integral augmented switching hyperplane is improved. The robustness is achieved, and the continuous control is realised by employing the improved observer without the chattering problem and the steady state error. The effectiveness of the improved observer is confirmed by the comparative experimental results.

• Journal of Communications and Networks
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• v.13 no.3
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• pp.205-210
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• 2011

This paper presents an approach to the construction of multiple-rate quasi-cyclic low-density parity-check (LDPC) codes. Parity-check matrices of the proposed codes consist of $q{\times}q$ square submatrices. The block rows and block columns of the parity-check matrix correspond to the hyperplanes (${\mu}$-fiats) and points in Euclidean geometries, respectively. By decomposing the ${\mu}$-fiats, we obtain LDPC codes of different code rates and a constant code length. The code performance is investigated in term of the bit error rate and compared with those of LDPC codes given in IEEE standards. Simulation results show that our codes perform very well and have low error floors over the additive white Gaussian noise channel.