• 한국정보통신학회논문지
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• 제23권2호
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• pp.117-126
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• 2019

부정맥 분류를 위한 기존 연구들은 분류의 정확성을 높이기 위해 신경망, 퍼지, 시계열 주파수 분석, 비선형 분석법 등이 연구되어 왔다. 이러한 방법들은 분류율를 향상시키기 위해 정확한 특징점과 많은 양의 신호를 처리해야 하기 때문에 데이터의 가공 및 연산이 복잡하며, 다양한 부정맥을 분류하는데 어려움이 있다. 본 연구에서는 AR(Auto Regressive) 모델링 기반의 특징점 추출과 SVM(Support Vector Machine)을 통한 조기수축 부정맥 분류 방법을 제안한다. 이를 위해 잡음을 제거한 ECG 신호에서 R파를 검출하고 QRS와 RR 간격의 특정 파형 구간을 모델링하였다. 이후 최적 세그먼트 길이(n1, n2), 최적 차수( p1, p2)의 4가지 AR 모델링 변수를 추출하고 SVM을 통해 Normal, PVC, PAC를 분류하였다. 연구의 타당성을 입증하기 위해 MIT-BIH 부정맥 데이터베이스를 대상으로 한 R파의 평균 검출 성능은 99.77%, Normal, PVC, PAC 부정맥은 각각 99.23%, 97.28, 96.62의 평균 분류율을 나타내었다.

• 제어로봇시스템학회논문지
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• 제13권7호
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• pp.631-636
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• 2007

An efficient obstacle avoidance algorithm is proposed in this paper to avoid dynamic obstacles using a collision vector while a tele-operated mobile robot is moving. For the verification of the algorithm, an operator watches through a monitor and controls the mobile robot with a force-reflection joystick. The force-reflection joystick transmits a virtual force to the operator through the Inter-net, which is generated by an adaptive impedance algorithm. To keep the mobile robot safe from collisions in an uncertain environment, the adaptive impedance algorithm generates the virtual force which changes the command of the operator by pushing the operator's hand to a direction to avoid the obstacle. In the conventional virtual force algorithm, the avoidance of moving obstacles was not solved since the operator cannot recognize the environment realistically by the limited communication bandwidth and the narrow view-angle of the camera. To achieve the dynamic obstacle avoidance, the adaptive virtual force algorithm is proposed based on the collision vector that is a normal vector from the obstacle to the mobile robot. To verify the effectiveness of the proposed algorithm, mobile robot navigation experiments with multiple moving obstacles have been performed, and the results are demonstrated.

• Journal of Computational Design and Engineering
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• 제2권3호
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• pp.129-136
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• 2015

This paper proposes a novel method for shape design of a Bezier surface with given boundary curves. The surface is defined as the minimizer of an extended membrane functional or an extended thin plate functional under the guidance of a specified normal field together with an initial prescribed surface. For given boundary curves and the guiding normal field, the free coefficients of a Bezier surface are obtained by solving a linear system. Unlike previous PDE based surface modeling techniques which construct surfaces just from boundaries, our proposed method can be used to generate smooth and fair surfaces that even follow a specified normal field. Several interesting examples are given to demonstrate the applications of the proposed method in geometric modeling.

• 한국자원식물학회지
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• 제17권2호
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• pp.161-168
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• 2004

Ferritin light heavy chain (FLHC) gene는 일부 중금속과 결합, 저장 및 운반하여 무독화 시킬 수 있는 것으로 알려져 있다. Fe 관련 유전자인 FLHC유전자를 식물 발현용 promoter인 35S promoter와 Tnos를 사용하여 식물 형질전환용 vector를 재조합하였다. 식물세포형질전환용 binary vector는 상기 cassette vector가 조립이 매우 양호하며 border sequence를 가지고 있는 pRD400 binary vector를 사용하여 최종적으로 가나마이신 내성 유전자 (NPT II gene)와 tadpole ferritin heavy chain gene 및 human ferritin light chain gene를 함유하고 있는 binary vector를 재조합하였다. Binary vector의 아그로박테리움에 도입은 triparental mating 방법에 의하여 수행하여 AB배지 및 가나마이신 함유 배지에서 disarmed Ti-vector를 가지고 있는 Agrobacterium tumefaciens MP90/FLHC을 선발하였다. FLHC 유전자 도입된 식물형질전환용 binary vector를 이용하여 형질전환방법을 변형하여 많은 embryo를 유도하였으며 유도된 embryo들은 GA 10mg/L가 첨가된 배지에 지상부를 유도하였다. 형질전환체식물체의 정상적인 생장을 유도하기 위해 최적의 배양조건을 조사하였던 바, 비교적 1/3 MS배지에서 뿌리의 생장과 지상부의 생장이 균일하게 생장하는 경향을 보였으며, 뿌리와 줄기가 잘 발달된 약 7cm의 유식물체를 대량으로 증식하여, 모래와 흙이 1:1로 혼합된 토양에 옮겼다.

• Structural Engineering and Mechanics
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• 제14권6호
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• pp.679-698
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• 2002

In this paper some techniques for the dynamic analysis of non-classically damped linear systems are reviewed and compared. All these methods are based on a transformation of the governing equations using a basis of complex or real vectors. Complex and real vector bases are presented and compared. The complex vector basis is represented by the eigenvectors of the complex eigenproblem obtained considering the non-classical damping matrix of the system. The real vector basis is a set of Ritz vectors derived either as the undamped normal modes of vibration of the system, or by the load dependent vector algorithm (Lanczos vectors). In this latter case the vector basis includes the static correction concept. The rate of convergence of these bases, with reference to a parametric structural system subjected to a fixed spatial distribution of forces, is evaluated. To this aim two error norms are considered, the first based on the spatial distribution of the load and the second on the shear force at the base due to impulsive loading. It is shown that both error norms point out that the rate of convergence is strongly influenced by the spatial distribution of the applied forces.

• Journal of Power Electronics
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• 제16권5호
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• pp.1773-1780
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• 2016

This paper proposes a wide air-gap control method for the multi-module permanent magnet linear synchronous motor (MM-PMLSM) based on independent vector control. In particular, the MM-PMLSM consists of symmetrical multi-module and multi-phase structures, which are basically three-phase configurations without a neutral point, unlike conventional three-phase machines. In addition, there are no additional magnetic levitation windings to control the normal force of the air-gap between each stator and mover. Hence, in this paper, a dq-axis current control applying a d-q transformation and an independent vector control are proposed for the air-gap control between the two symmetric stators and mover of the MM-PMLSM. The characteristics and control performance of the MM-PMLSM are analyzed under the concept of vector control. As a result, the proposed method is easily implemented without additional windings to control the air-gap and the mover position. The effectiveness of the proposed independent vector control algorithm is verified through experimental results.

• Toxicological Research
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• 제19권3호
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• pp.247-257
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• 2003

Medicine is undergoing a revolution in the understanding of the mechanisms through which disease processes develop. The advent of genetics and molecular biology to oncology not only is providing surrogate predictors of therapy response and survival which are forming the basis for selection among established treatment options, but is providing targets for new directions in therapy as well. Molecular modification of somatic cells for the purposes of protecting the normal cells from the toxicity of cancer chemotherapy, for the sensitization of the tumor cells to therapy and use of conditionally replicating viral vector have been new directions of cancer treatment which have reached the clinical arena. Advances in molecular pharmacology and vector design summarized in this paper may provide solutions to some of the existing problems in the technology of gene transfer therapy. Continued basic research into the biological basis of human disease, systemic studies of the application of these discoveries to therapy and the improvement of vector for gene delivery all combined may result in advances in this important field of therapy over the next few years.

• 호남수학학술지
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• 제38권3호
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• pp.467-477
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• 2016

In this paper, we study the timelike Bertrand curves in Minkowski 3-space. Since the principal normal vector of a timelike curve is spacelike, the Bertrand mate curve of this curve can be a timelike curve, a spacelike curve with spacelike principal normal or a Cartan null curve, respectively. Thus, by considering these three cases, we get the necessary and sufficient conditions for a timelike curve to be a Bertrand curve. Also we give the related examples.

• 대한수학회논문집
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• 제18권2호
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• pp.309-323
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• 2003

In this paper, We characterize a semi-invariant sub-manifold of codimension 3 satisfying ∇$\varepsilon$A = 0 in a complex projective space CP$\^$n+1/, where ∇$\varepsilon$A is the covariant derivative of the shape operator A in the direction of the distinguished normal with respect to the structure vector field $\varepsilon$.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.121-126
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• 2008

A plane strain problem of a crack on interface between an isotropic elastic conductor and a transversely isotropic piezoelectric ceramics is considered. The problem is reduced to system integrodifferential equations on the interface. These equations relate the normal and tangential components of the crack opening vector with distribution of normal and shear stresses on the crack surfaces. It therefore make it possible to obtain an exact solution as a function of the loading applied to the crack surfaces. As an example, some analytical solutions of the crack problem are given.