• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.84-84
• /
• 2000

This paper proposes a new impedance control scheme based on a variable stiffness matrix for a bilateraL teleoperation. In this scheme, stiffness matrix of the impedance model in the slave is modulated based on the distance, measured by an ultrasonic sensor, between the slave and environment. At the same time, the stiffness matrix of the master is also changed accordingly in order for the impedance parameters of the combined system to remain constant The proposed scheme is implemented on a 1-dof master/slave system to perform a simple task. In the experiments, the teleoperator with the impedance parameter modulation shows better performance than one with fixed impedance parameters, especially in reducing task execution time and in avoiding excessive external forces.

• 정보처리학회논문지A
• /
• 제11A권2호
• /
• pp.189-194
• /
• 2004

본 논문은 다량의 고차원 얼굴 표정 모션 데이터를 2차원 공간에 분포시키고, 애니메이터가 이 공간을 항해하면서 원하는 표정들을 실시간 적으로 선택함으로써 얼굴 표정 애니메이션을 생성하는 방법을 기술한다. 본 논문에서는 약 2400여개의 얼굴 표정 프레임을 이용하여 표정공간을 구성하였다. 표정공간의 생성은 임의의 두 표정간의 최단거리의 결정으로 귀결된다. 표정공간은 다양체 공간으로서 이 공간내의 두 점간의 거리는 다음과 같이 근사적으로 표현한다. 임의의 마커간의 거리를 표시하는 거리행렬을 사용하여 각 표정의 상태를 표현하는 표정상태벡터를 정의한 후, 두 표정이 인접해 있으면, 이를 두 표정 간 최단거리(다양체 거리)에 대한 근사치로 간주한다. 그리하여 인접 표정들 간의 인접거리가 결정되면, 이틀 인접거리들을 연결하여 임의의 두 표정 상태간의 최단거리를 구하는데, 이를 위해 Floyd 알고리즘을 이용한다. 다차원 공간인 표정공간을 가시화하기 위해서는 Sammon 매핑을 이용하여 2차원 평면에 투영시켰다. 얼굴 애니메이션은 사용자 인터페이스를 사용하여 애니메이터들이 2차원 공간을 항해하면서 실시간으로 생성한다.

• Kyungpook Mathematical Journal
• /
• 제59권2호
• /
• pp.335-340
• /
• 2019

The energy of a graph G is the sum of the absolute values of the eigenvalues of the adjacency matrix of G. Some variants of energy can also be found in the literature, in which the energy is defined for the Laplacian matrix, Distance matrix, Commonneighbourhood matrix or Seidel matrix. The Seidel matrix of the graph G is the square matrix in which $ij^{th}$ entry is -1 or 1, if the vertices $v_i$ and $v_j$ are adjacent or non-adjacent respectively, and is 0, if $v_i=v_j$. The Seidel energy of G is the sum of the absolute values of the eigenvalues of its Seidel matrix. We present here some families of pairs of graphs whose Seidel matrices have different eigenvalues, but who have the same Seidel energies.

• 전자통신동향분석
• /
• 제13권4호통권52호
• /
• pp.59-69
• /
• 1998

The terminology of data prefetching is introduced, which includes stride, repeat distance, stall, pending stall, prefetch degree, prefetch distance, and prefetch offset. The effectiveness of hardware data prefetching in reducing cache misses is shown by presenting a square matrix multiplication example. Thereafter the pitfalls of prefetching and possible solutions are discussed.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제9권9호
• /
• pp.3611-3634
• /
• 2015

In this paper, we build a theoretical framework for quantitatively measuring and graphically representing the degrees of closeness centralization among performers assigned to enact a workflow procedure. The degree of closeness centralization of a workflow-performer reflects how near the performer is to the other performers in enacting a corresponding workflow model designed for workflow-supported organizational operations. The proposed framework comprises three procedural phases and four functional transformations, such as discovery, analysis, and quantitation phases, which carry out ICN-to-WsoN, WsoN-to-SocioMatrix, SocioMatrix-to-DistanceMatrix, and DistanceMatrix-to-CCV transformations. We develop a series of algorithmic formalisms for the procedural phases and their transformative functionalities, and verify the proposed framework through an operational example. Finally, we expatiate on the functional expansion of the closeness centralization formulas so as for the theoretical framework to handle a group of workflow procedures (or a workflow package) with organization-wide workflow-performers.

• 한국컴퓨터정보학회논문지
• /
• 제19권4호
• /
• pp.91-99
• /
• 2014

본 논문은 2차 할당 문제의 최적 해를 찾을 수 있는 휴리스틱 다항시간 알고리즘을 제안하였다. 일반적으로 선형 할당 문제의 최적 해는 헝가리안 알고리즘으로 구한다. 그러나 2차 할당문제의 최적 해를 찾는 알고리즘은 제안되지 않고 있다. 제안된 알고리즘은 거리행렬의 단위거리로부터 그리드 형태의 배치를 찾아내고, 이 형태에 맞도록 흐름량 행렬의 최대 값부터 내림차순으로 최대흐름을 최소 거리에 배치하는 최대흐름/최소거리 기법을 적용하였다. 제안된 알고리즘을 다양한 그리드형 2차 할당문제에 적용한 결과 2차 할당문제의 해를 다항시간에 구할 수 있는 알고리즘이 존재할 가능성을 보였다.

• 한국정보통신학회논문지
• /
• 제23권10호
• /
• pp.1290-1297
• /
• 2019

본 논문에서는 ultra-wideband(UWB) 시스템에서 합성곱 신경망(CNN)을 이용한 거리 추정 기법을 제안한다. 제안하는 기법은 UWB 신호를 이용하여 송신기와 수신기 사이의 거리를 추정하기 위하여 수신신호의 크기 샘플로 이루어진 1차원 벡터를 2차원 행렬로 재구성하며, 이 2차원 행렬로부터 합성곱 신경망 회귀를 이용하여 거리를 추정한다. IEEE 802.15.4a 표준의 UWB 실내 가시선 채널모델을 이용하여 수신신호를 생성하여 학습데이터를 만들며 합성곱 신경망 모델을 학습시킨다. 또한 실제 필드 시험을 통해 실내환경에서의 실험 데이터를 이용하여 거리추정 성능을 확인한다. 제안하는 기법은 기존의 문턱값 기반의 거리 추정 기법과의 성능비교도 수행하는데, 결과에 따르면 10m 거리에서 제안기법은 0.6m의 제곱근 평균 자승 에러를 보이는데 기존기법은 1.6m로 훨씬 큰 에러를 보인다.

• 로봇학회논문지
• /
• 제3권3호
• /
• pp.237-244
• /
• 2008

Nowadays, research on human-robot interaction has been getting increasing attention. In the research field of human-robot interaction, speech signal processing in particular is the source of much interest. In this paper, we report a speaker localization system with six microphones for a humanoid robot called MAHRU from KIST and propose a time delay of arrival (TDOA)-based feature matrix with its algorithm based on the minimum sum of absolute errors (MSAE) for sound source localization. The TDOA-based feature matrix is defined as a simple database matrix calculated from pairs of microphones installed on a humanoid robot. The proposed method, using the TDOA-based feature matrix and its algorithm based on MSAE, effortlessly localizes a sound source without any requirement for calculating approximate nonlinear equations. To verify the solid performance of our speaker localization system for a humanoid robot, we present various experimental results for the speech sources at all directions within 5 m distance and the height divided into three parts.

• Communications for Statistical Applications and Methods
• /
• 제24권3호
• /
• pp.317-324
• /
• 2017

An influence measure known as Cook's distance has been used for judging the influence of each observation on the least squares estimate of the parameter vector. The distance does not reflect the distributional property of the change in the least squares estimator of the regression coefficients due to case deletions: the distribution has a covariance matrix of rank one and thus it has a support set determined by a line in the multidimensional Euclidean space. As a result, the use of Cook's distance may fail to correctly provide information about influential observations, and we study some reasons for the failure. Three illustrative examples will be provided, in which the use of Cook's distance fails to give the right information about influential observations or it provides the right information about the most influential observation. We will seek some reasons for the wrong or right provision of information.

• 대한수학회보
• /
• 제54권2호
• /
• pp.507-519
• /
• 2017

We present an upper bound on the Cheeger constant of a distance-regular graph. Recently, the authors found an upper bound on the Cheeger constant of distance-regular graph under a certain restriction in their previous work. Our new bound in the current paper is much better than the previous bound, and it is a general bound with no restriction. We point out that our bound is explicitly computable by using the valencies and the intersection matrix of a distance-regular graph. As a major tool, we use the discrete Green's function, which is defined as the inverse of ${\beta}$-Laplacian for some positive real number ${\beta}$. We present some examples of distance-regular graphs, where we compute our upper bound on their Cheeger constants.