• Title/Summary/Keyword: model singularity

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A Study on Energy Efficiency Plan based on Artificial Intelligence: Focusing on Mixed Research Methodology (인공지능 기반 에너지 효율화 방안 연구: 혼합적 연구방법론 중심으로)

  • Lee, Moonbum;Ma, Taeyoung
    • Journal of Information Technology Services
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    • v.21 no.5
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    • pp.81-94
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    • 2022
  • This study sets the research goal of reducing energy consumption which 'H' University Industry-University Cooperation Foundation and resident companies are concerned with, as well as conducting policy research and data analysis. We tried to present a solution to the problem using the technique. The algorithm showing the greatest reliability in the power of the model for the analysis algorithm of this paper was selected, and the power consumption trend curves per minute and hour were confirmed through predictive analysis while applying the algorithm, as well as confirming the singularity of excessive energy consumption. Through an additional sub-sensor analysis, the singularity of energy consumption of the unit was identified more precisely in the facility rather than in the building unit. Through this, this paper presents a system building model for real-time monitoring of campus power usage, and expands the data center and model for implementation. Furthermore, by presenting the possibility of expanding the field through research on the integration of mobile applications and IoT hardware, this study will provide school authorities and resident companies with specific solutions necessary to continuously solve data-based field problems.

Kinematic Modeling and Analysis of Omni-Directional Mobile Robots with Redundant Actuation (여유구동을 지니는 전방향 모바일 로봇의 기구학 모델링 및 해석)

  • Yi, Byung-Ju;Kim, Wheekuk;Yang, Seong-Il
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.9
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    • pp.766-773
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    • 2001
  • Omni-directional mobile robots have been popularly employed in several application areas. However, the kinematics for these systems have not been clearly identified, specially for redundantly actuated case which is common in omni-directional mobile robot such as the Nomadic model. For such mobile robot systems, exploitation of redundant actuation as well as singularity analysis has not been extensively addressed. In light of this fact, this paper introduces two different kinematic approaches for omni-directional mobile robots. Then, a singular-free load distribution scheme for redundantly actuated three-wheeled omni-directional mobile robot is proposed. Through simulation, several advantages of redundantly actuated mobile robot in aspect of singularity avoidance, minimization of torque norm, and exploiting several subtasks are presented.

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The Stress Analysis of Dissimilar Materials in Brazed Interface by BEM (이종재 브레이징 접합계면의 응력해석)

  • 오환섭;김시현;김성재
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.769-772
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    • 1997
  • In this study, By employing two dimensional(2-D) Boundary Element Method(BEM) stress analysis was carried to investigate stress distributions on the brazing joint of a Hardmetal and a HSS. Two model was proposed to analyze stress singularity in brazed interface. The stress results from the BEM were considered influence of the kind of materials , thickness of filled metal and length of vertical brazing adhesive. From those obtained results , the peak point of stress was founded in the lower part of two interface was made by brazing. As the thickness and length changed, the maximum stress tended to change in the peak point.

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A Study of 2-D Eddy Current Problem Using Boundary Element Method (경계요소법을 이용한 2차원 와전류 문제에 대한 연구)

  • Lim, Eui-Soo;Lee, Hyang-Beom
    • Proceedings of the KIEE Conference
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    • 1999.07a
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    • pp.217-219
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    • 1999
  • This paper presents a study of 2-dimensional(2-D) eddy current problem using boundary element method(BEM). When compared with finite element method(FEM), there are only a few unknown variables in BEM because it implements numerical analysis only for the surface or boundary of a model. As a result, a lot of computational memory and time can be saved. In order to analyze 2-D eddy current problem, potentials and its derivatives(flux) in a boundary are used as variables. The Mantel function of the second kind of the zero order is used here as a fundamental solution. In order to remove singularity and to solve the integral equations in a boundary, Subtracting Singularity Method and Gauss Quadrature Formula are adopted in this paper.

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Viscoelastic Analysis of Stress Intensity Factor for Interface Edge Crack in a Unidirectional Liminate (단일방향 복합재료의 공유면에 존재하는 계면 모서리균열의 점탄성 해석)

  • 이상순;김범식
    • Computational Structural Engineering
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    • v.10 no.1
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    • pp.129-134
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    • 1997
  • Interfacial stress singularity in a unidirectional two-dimensional laminate model consisting of an elastic fiber and a viscoelastic matrix has been investigated using the time-domain boundary element method. First, the interfacial singular stresses between the fiber and the matrix of a unidirectional laminate subjected to a uniform transverse tensile strain have been investigated near the free surface, but without any defect or any edge crack. Such a stress singularity might lead to fiber-matrix debonding or interfacial edge cracks. Then, the overall stress intensity factor for the case of a small interfacial edge crack of length a has been computed.

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Analysis of Hygrothermal Stresses in a Viscoelastic Thin Film

  • Lee, Sang-Sun
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2003.12a
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    • pp.146-153
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    • 2003
  • This paper deals with the stress singularity induced at the interface corner between the viscoelastic thin film and the rigid substrate subjected to the combined influence of temperature change and moisture absorption. A boundary element analysis is employed to investigate the behavior of interface stresses. The film is assumed to be thermorheologically simple. It is further assumed that moisture effects are analogous to thermal effects. Numerical results are presented for a given viscoelastic model, indicating the singular residual stresses induced during cooling down from the curing temperature, and how they can be altered by subsequent moisture absorption at room temperature.

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COLLOCATION APPROXIMATIONS FOR INTEGRO-DIFFERENTIAL EQUATIONS

  • Choi, Moon-Ja
    • Bulletin of the Korean Mathematical Society
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    • v.30 no.1
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    • pp.35-51
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    • 1993
  • This paper concerns collocation methods for integro-differential equations in which memory kernels have a singularity at t = 0. There has been extensive research in recent years on Volterra integral and integro-differential equations for physical systems with memory effects in which the stabilty and asymtotic stability of solutionsl have been the main interest. We will study a class of hereditary equations with singular kernels which interpolate between well known model equations as the order of singularity varies. We are also concerned with the smoothing effect of singular kernels, but we use energy methods and our results involve fractional time in fixed spatial norms. Galerkin methods for our models was studied and existence, uniqueness and stability results was obtained in [4]. Our major goal is to study collocation methods.

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Viscoelastic Analysis of an Interface Edge Crack in a Bonded Polymeric Film

  • Lee, Sang-Soon
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.3
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    • pp.35-39
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    • 2010
  • Interfacial stress singularity induced in an analysis model consisting of the polymeric thin film and the elastic substrate has been investigated using the boundary element method. The interfacial singular stresses between the viscoelastic thin film and the elastic substrate subjected to a uniform moisture ingression are investigated for the case of a small interfacial edge crack. It is assumed that moisture effects are assumed to be analogous to thermal effects. Then, the overall stress intensity factor for the case of a small interfacial edge crack is computed. The numerical procedure does not permit calculation of the limiting case for which the edge crack length vanishes.

Structural Equation Modeling on Case Management Outcomes and Factors Influencing Outcomes in the Community-dwelling Vulnerable Elders (취약계층 재가노인의 사례관리 성과와 영향요인에 관한 구조모형 구축)

  • Moon, Hyunjung;Lee, In-Sook
    • Journal of Korean Academy of Nursing
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    • v.43 no.6
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    • pp.791-800
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    • 2013
  • Purpose: This study was done to test a structural equation modeling of case management outcomes in order to identify parameters affecting case management outcomes for the community-dwelling vulnerable elders. Methods: Data were collected from 309 nurses (case managers) and community-dwelling vulnerable elders (clients) from public health centers. For data analysis, descriptive statistics, Pearson correlation analysis, factor analysis, and covariance structure analysis were performed using SPSS Version 18.0 for Windows and Amos 16.0. Results: The hypothetical model had an acceptable fit: GFI=.97, CFI=.95, RMSEA=.02, SRMR=.05. The factor "case managers' singularity" had the greatest impact on case management outcomes in this model. In addition, the factor "case management practice" influenced case management outcomes; however, client characteristics did not. Case managers' singularity affected case management outcomes directly and indirectly, with case management practice mediating the latter effect. Conclusion: These results suggest that the causal relationship between case management outcomes and factors influencing these outcomes should be clarified through longitudinal research including a variety of client characteristics. In addition, in future studies, analysis of the effects of programs to improve manpower quality and examine the relationships among case management outcomes should be done.

Study on Low Frequency Swishing Sound Field by a Singularity in Circular Motion with Large Radius (큰 반경의 원운동을 하는 점 음원에 의한 저주파수 스위싱 음장 분석)

  • Lee, Gwang-Se;Cheong, Cheolung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.7
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    • pp.569-574
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    • 2014
  • In order to investigate low frequency swishing noise of wind turbines, acoustic source model using a singularity in circular motion is introduced to derive analytic solution of Lowson acoustic analogy in time domain. Results in time and frequency domains computed by the solution show apparent modulation of amplitude and frequency. The solution indicates that time histories of acoustic pressure at receiver points varied significantly according to receiver's directional location, even when the retarded time distributions are similar. However, the corresponding time-averaged spectra of sound pressure at the receiver locations where the retarded time distributions are almost same are not significantly different. It can be inferred from these results that the time-averaged sound pressure spectra which cannot take into account the detailed difference in the time-variation of wind turbine noise may not represent the sound quality of wind turbines due to its swishing. Finally, as an introduction of procedure to quantify low frequency swishing noise level, relative variation of overall sound pressure level is obtained using tonal low frequency noise model.