• Title/Summary/Keyword: theoretical models

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Stress Smoothing by Kriging Interpolation (Kriging 보간법에 의한 응력 평활화)

  • 이동진;홍종현;이채규;우광성
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.317-324
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    • 2003
  • Kriging interpolation is one of the gennerally used interpolation techniques in Geostatics field. This research refers to the contents about important experimental variogram and the study of theoretical variogram and formulation of Kriging interpolation. Kriging interpolation is applied as interpolation for stress smoothing in finite element method. Posteriori error estimation which makes use of stress smoothing from the FEM is very important part, we try to make practical application of surface regeneration ability from Kriging interpolation. This research is necessary preceding one in order to materialize adaptive FTM through posteriori error estimation. For instance, find the estimate value and estimate the propriety through various theoretical variogram models of the reference analyzed from tensional L-shape domain. It also provides possibility of the Kriging interpolation through comparing to existing Least square method as well.

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Marine Crime and Business Cycle (해상범죄와 경기변동)

  • 나호수
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.7 no.3
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    • pp.107-116
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    • 2001
  • The relatively rapid rising trends of crime rates in marine situations leads to social concerns in Korea. This study reviews some theoretical backgrounds of the economics of crime and apply econometric models to Korean marine crimes. We find that there is a positive relationship between marine crime rates and unemployment rates in Korea and the degree of the relationship is higher in the 1990s' in comparison with the results of 1970s' and 1980s'. This findings are compatible with the previous theoretical researches in advanced countries. These findings show that recently the structure of our economy and the economic behaviors of economic agents in Korea have been similar to those of the advanced economies. Therefore this study shows that there exists the additional social costs of economic depression by causing the social crimes and the necessity of public policies to reduce unemployment rates would be higher.

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Theoretical Aspects of PTC Thermistors

  • Cho, Sang-Hee
    • Journal of the Korean Ceramic Society
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    • v.43 no.11 s.294
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    • pp.673-679
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    • 2006
  • The discovery of ferroelectric barium titanate (BaTiO$_3$) in 1942 began the present era of dielectrics-based electronic ceramics. Ferroelectric barium titanate has a high dielectric constant and after the recognition of BaTiO$_3$ as a new ferroelectric compound, various attractive electrical properties have been extensively studied and reported. Since then, pioneering work on valence-compensated semiconduction led to the discovery of the positive temperature coefficient (PTC) of the resistance effect found in doped BaTiO$_3$. Significant progress has since followed with respect to understanding the PTC phenomena, advancing materials capabilities, and developing devices for sensor and switching applications. In this paper, the theoretical aspects of the various PTC models are discussed and the future trends of practical applications for PTC devices are briefly mentioned.

Computational Challenges for Integrative Genomics

  • Kim, Junhyong;Magwene, Paul
    • Genomics & Informatics
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    • v.2 no.1
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    • pp.7-18
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    • 2004
  • Integrated genomics refers to the use of large-scale, systematically collected data from various sources to address biological and biomedical problems. A critical ingredient to a successful research program in integrated genomics is the establishment of an effective computational infrastructure. In this review, we suggest that the computational infrastructure challenges include developing tools for heterogeneous data organization and access, innovating techniques for combining the results of different analyses, and establishing a theoretical framework for integrating biological and quantitative models. For each of the three areas - data integration, analyses integration, and model integration - we review some of the current progress and suggest new topics of research. We argue that the primary computational challenges lie in developing sound theoretical foundations for understanding the genome rather than simply the development of algorithms and programs.

Determination of Physical Dimensions of ${\mu}$ Cassiopeiae

  • Bach, Kie-Hunn;Kang, Won-Seok
    • Bulletin of the Korean Space Science Society
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    • 2010.04a
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    • pp.35.1-35.1
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    • 2010
  • Using the spectroscopic analysis and the theoretical modeling, physical properties of the nearby astrometric binary $\mu$ Cas have been determined. In spite of the well-defined parallax and astrometric orbit, there has been a chronic mass ratio problem between components. Recently, the radius of the primary component has been detected from the optical interferometric observation of the CHARA array. Using the high resolution spectroscopic analysis, we found that $\mu$ Cas have $\alpha$-enhanced chemical composition with respect to the scaled solar abundance by a factor of two. Combining our abundance analysis with recently determined physical properties, the consistent models for $\mu$ Cas have been constructed within the frame work of standard stellar theory. Through a statistical minimization between theoretical model grids, a reliable set of physical dimensions has been defined. Furthermore, the mode oscillation frequency of the best model has been calculated.

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Thermo-optic Effects of Optical Temperature Sensor (광 온도센서의 열전.광 효과)

  • Lee, Kwang-Seok;Kim, Hyun-Deok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.11
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    • pp.2049-2054
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    • 2006
  • This paper demonstrates a comparison of linear and nonlinear analyses for thermo-optic effects of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include theoretical analyses and experiment of the etched planar waveguide Bragg grating optical temperature sensor, Theoretical models with nonlinear than linear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.

Theoretical and experimental research of external prestressed timber beams in variable moisture conditions

  • Miljanovic, Sladana;Zlatar, Muhamed
    • Coupled systems mechanics
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    • v.4 no.2
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    • pp.191-209
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    • 2015
  • Hybrid girders can be constructed in different geometrical forms and from different materials. Selection of beam's effective constellation represents a complex process considering the variations of geometrical parameters, changes of built in material characteristics and their mutual relations, which has important effect on the behavior of the girder. This paper presents the theoretical and experimental research on behavior of the timber-steel hybrid girders' different geometrical constellation with external prestressing and in different conditions of timber moisture. These researches are based on linear elastic analysis, and further refine by using the plasticity and damage models.

Comparison among different software for the evaluation of moment-curvature of R.C. columns

  • Montuori, Rosario;Nastri, Elide;Palese, Maria Ilenia;Piluso, Vincenzo
    • Computers and Concrete
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    • v.24 no.3
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    • pp.259-269
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    • 2019
  • The work aims at the comparison among commonly used research programs concerning moment-curvature ($M-{\chi}$) diagrams of confined R.C. members. The software considered in this work are Sap2000, SeismoStruct and Opensees. The curves provided by these software, given the same modelling, have been compared to those provided by a theoretical fiber model. A parametric analysis has been led on rectangular column sections with different level of axial load and different stirrups spacing. The accuracy of the modelling of the considered structural programs has been investigated by comparing their results with those obtained by applying the theoretical fiber model.

Maximum cavity radius prediction model generated by drop impact in an inclined bath (기울어진 수조에 액적 충돌로 발생한 최대 공동 예측 모델)

  • Lee, Yeawan;Kim, Youngdo;Kim, Hyoungsoo
    • Journal of the Korean Society of Visualization
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    • v.17 no.2
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    • pp.83-89
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    • 2019
  • In this study, we show the maximum cavity radius prediction model that a droplet impacts an inclined bath. Surface tensions, viscosities, inclination angles of a bottom substrate, droplet diameters, falling heights of the droplet are varied for the experiment. We experimentally observe that the cavity grows in hemispherical shape like the cavity formed in a deep bath although the depth of the bath is non-uniform due to an inclined bottom substrate. We derive two theoretical models to predict the experimental results of the fully developed cavity. Although each model has error, we observe that qualitatively theoretical model predicts the trend of experiment results well.

Predictions of the maximum plate end stresses of imperfect FRP strengthened RC beams: study and analysis

  • Rabia, Benferhat;Daouadji, Tahar Hassaine;Abderezak, Rabahi
    • Advances in materials Research
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    • v.9 no.4
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    • pp.265-287
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    • 2020
  • A theoretical method to predict the interfacial stresses in the adhesive layer of reinforced concrete beams strengthened with porous FRP plate is presented in this paper. The effect due to porosity is incorporated utilizing a new modified rule of mixture covering the porosity phases. The adherend shear deformations have been included in the present theoretical analyses by assuming a linear shear stress through the thickness of the adherends. Remarkable effect of the porosity has been noted in the results. Indeed, the resulting interfacial stresses concentrations are considerably smaller than those obtained by other models which neglect the porosity effect. It was found that the interfacial stresses are highly concentrated at the end of the FRP plate, the minimization of the latter can be achieved by using porous FRP plate in particular at the end. It is also shown that the interfacial stresses of the RC beam increase with volume fraction of fibers, but decrease with the thickness of the adhesive layer.