• Title/Summary/Keyword: Plastic model

Search Result 2,246, Processing Time 0.031 seconds

S/W model of Plastic Slice for Semi-federated Slice Control of Future Internet Testbed (미래인터넷 테스트베드의 Semi-federated Slice Control을 위한 Plastic Slice의 S/W 모델)

  • Cha, Byung-Rae;Kim, Jong-Won
    • Journal of Advanced Navigation Technology
    • /
    • v.16 no.5
    • /
    • pp.817-830
    • /
    • 2012
  • In rapid changes in communications and computing environment, due to the increasing variety of user requirements, and an effort to solve the fundamental problems with the current Internet, Future Internet researches actively have been performed at domestic and abroad. In this paper, we proposed the idea and basic concept of Plastic slice software mode about federation job control in study topic of future internet.

Effect of Plastic Gradient from GND on the Behavior of Polycrystalline Solids (GND 효과에 의한 소성 구배의 다결정 고체 거동에 대한 영향)

  • Chung, Sang-Yeop;Han, Tong-Seok
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.24 no.2
    • /
    • pp.185-191
    • /
    • 2011
  • Plastic gradient from geometrically necessary dislocation(GND) can affect material behavior significantly. In this research, mechanical behavior of polycrystalline solid is investigated using the finite element method incorporating plastic gradient from long range dislocation or GND effect. Plastic gradient effect is implemented in the analysis model by considering a long range strain term as well as elastic and plastic terms in the multiplicative decomposition. In the model, gradient hardness coefficient and length parameter are used to evaluate the effect of the long range strains and sensitive study is conducted for the parameters. It is confirmed that the GND amplifies hardening response of polycrystals compared with the single crystal.

Research Priorities in Light of Current Trends in Microsurgical Training: Revalidation, Simulation, Cross-Training, and Standardisation

  • Nicholas, Rebecca Spenser;Madada-Nyakauru, Rudo N.;Irri, Renu Anita;Myers, Simon Richard;Ghanem, Ali Mahmoud
    • Archives of Plastic Surgery
    • /
    • v.41 no.3
    • /
    • pp.218-224
    • /
    • 2014
  • Plastic surgery training worldwide has seen a thorough restructuring over the past decade, with the introduction of formal training curricula and work-based assessment tools. Part of this process has been the introduction of revalidation and a greater use of simulation in training delivery. Simulation is an increasingly important tool for educators because it provides a way to reduce risks to both trainees and patients, whilst facilitating improved technical proficiency. Current microsurgery training interventions are often predicated on theories of skill acquisition and development that follow a 'practice makes perfect' model. Given the changing landscape of surgical training and advances in educational theories related to skill development, research is needed to assess the potential benefits of alternative models, particularly cross-training, a model now widely used in non-medical areas with significant benefits. Furthermore, with the proliferation of microsurgery training interventions and therefore diversity in length, cost, content and models used, appropriate standardisation will be an important factor to ensure that courses deliver consistent and effective training that achieves appropriate levels of competency. Key research requirements should be gathered and used in directing further research in these areas to achieve on-going improvement of microsurgery training.

The Critical Pigment Volume Concentration Concept for Paper Coatings: I. Model Coating Systems Using Plastic Pigments and Latex Binders for Paper Coating Applications

  • Lee, Do-Ik
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.34 no.5
    • /
    • pp.1-17
    • /
    • 2002
  • The immobilization and consolidation of the model coatings based on the plastic pigment and latex binder of known particle sizes were theoretically Studied in terms of the dense random packing of binary spheres and varying extent of latex film shrinkage. The porosity of the model coatings was calculated based on three proposed latex shrinkage models: Maximum, Minimum, and Linearly Decreasing Latex Shrinkage. The increasing extent of latex shrinkage was calculated up to the critical pigment volume concentration(CPVC) as a function of plastic pigment volume fractions, and the maximum latex shrinkage was estimated from the CPVC. Also, the number of pores and the average equivalent spherical pore diameters were calculated based on those proposed models. The opacity and gloss of the model coatings on polyester films were measured and their porosity was also determined by a simple coat weight-thickness method. As expected, various coating structure-property-composition relationships, such as opacity, gloss, porosity, etc., were shown to exhibit sharp transitions near the CPVC. The CPVC values determined by the opacity, gloss, and porosity vs. PVC relationships, respectively, agreed very well with each other. Especially, the CPVC's determined by the opacity and porosity vs. PVC curves were identical. The comparison between the theoretically calculated and experimental porosity values showed that the intermediate value between the maximum and minimum latex shrinkage would best fit the experimental porosity data. The effect of plastic pigment particle size on the optical properties and porosity of model coatings was also studied and it was observed that the coating opacity and porosity increased with increasing plastic pigment particle size, but the gloss decreased. The ink gloss of the uncalendered model coatings applied onto commercial sheet offset coated papers was shown to be affected by both the coating gloss and porosity: the higher the coating gloss, the higher the ink gloss, but the higher the coating porosity, the lower the ink gloss. Their printability was also studied in terms of the number of passes-to-fail and the rate of ink setting as a function of both plastic pigment volume fractions and plastic pigment particle sizes. A minimum crack-free temperature(MCR) of latex-bound coatings was proposed to better predict the behaviors of latexes as coating binders. The wet state of model coating dispersions, the surfaces of consolidated model coatings, and their internal structure were examined by both electron and atomic force microscopy, and their micrographs were found to be consistent with our immobilization and consolidation models.

Analysis of solar radiation and simulation of thermal environment in plastic greenhouse - I. Analysis of solar radiation in plastic greenhouse (플라스틱 온실(溫室)의 일사량분석(日射量分析)과 열적환경(熱的環境)의 시뮬레이션에 관(關)한 연구(硏究) - I. 플라스틱 온실(溫室)의 일사량분석(日射量分析))

  • Park, Jae-Bok;Koh, Hak-Kyun
    • Solar Energy
    • /
    • v.6 no.2
    • /
    • pp.22-32
    • /
    • 1986
  • This study was carried out to analyze solar radiation in plastic greenhouse which is covered with polyethylene or polyvinyl chrolide film. A computer model for solar radiation analysis in the plastic greenhouse was developed and solar gain factors for E-W and N-S oriented plastic greenhouse in the greenhouse farming area during winter were investigated. Solar gain factors for E-W plastic greenhouse were 60 to 75 percent which were 10 to 15 percent higher than those for N-S plastic greenhouse from November to January. However, the values were apparently decreased in February and reversed in March, showing 3 to 5 percent higher in E-W plastic greenhouse. About 67 to 72 percent of the total solar radiation was attributed to the south-directed wall and roof for the E-W plastic greenhouse and about 30 percent through walls and 60 percent through roofs for the N-S plastic greenhouse.

  • PDF

A Study of Physical Condition Predicting Model Development of Plastic Pipes in Water Mains (플라스틱 관종의 물리적 상태예측모형 개발)

  • Ki, Nam-Yeoun;Bae, Cheol-Ho;Lee, Doo-Jin;Jung, Kwan-Sue
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.26 no.6
    • /
    • pp.871-881
    • /
    • 2012
  • This study suggested a model that can predict a degradation condition over time of two plastic pipes, PE and PVC, which are currently used in the country. This study was analyzed physical characteristics change of plastic pipes by comparison with initial physical characteristics (on the case of new pipes). Since this is dependent on accidents that already occurred, there are limitations that it only decides a priority on improvement based on relative corrosion status rather than precautionary aspects. The comparison results between physical degradation by the deducted performance rating and a conventional numerical scoring method showed that correlation coefficient was 0.67 for PE pipes and 0.86 for PVC pipes, indicating a high correlation. According to this result, it has been decided that the performance rating suggested herein can be applied naturally to the criterion of an improvement decision, which was based on Scoring System. From results of the research, it is expected that a reliable result can be provided to an improvement decision process related to degradation of plastic pipes by comprehensively comparing and evaluating a condition of pipe materials(direct factors) and an environmental impact(indirect factors).

Seismic response of bridge pier supported on rocking shallow foundation

  • Deviprasad, B.S.;Dodagoudar, G.R.
    • Geomechanics and Engineering
    • /
    • v.21 no.1
    • /
    • pp.73-84
    • /
    • 2020
  • In the seismic design of bridges, formation of plastic hinges plays an important role in the dissipation of seismic energy. In the case of conventional fixed-base bridges, the plastic hinges are allowed to form in the superstructure alone. During seismic event, such bridges may be safe from collapse but the superstructure undergoes significant plastic deformations. As an alternative design approach, the plastic hinges are guided to form in the soil thereby utilizing the inevitable yielding of the soil. Rocking foundations work on this concept. The formation of plastic hinges in the soil reduces the load and displacement demands on the superstructure. This study aims at evaluating the seismic response of bridge pier supported on rocking shallow foundation. For this purpose, a BNWF model is implemented in OpenSees platform. The capability of the BNWF model to capture the SSI effects, nonlinear behavior and dynamic loading response are validated using the centrifuge and shake table test results. A comparative study is performed between the seismic response of the bridge pier supported on the rocking shallow foundation and conventional fixed-base foundation. Results of the study have established the beneficial effects of using the rocking shallow foundation for the seismic response analysis of the bridge piers.

Prediction of the Macroscopic Plastic Strain Ratio in AA1100 Sheets Manufactured by Differential Speed Rolling (이속압연에 의해 제조된 AA1100 판재의 소성변형비 예측)

  • Choi, Jae-Kwon;Cho, Jae-Hyung;Kim, Hyoung-Wook;Kang, Seok-Bong;Choi, Shi-Hoon
    • Korean Journal of Metals and Materials
    • /
    • v.48 no.7
    • /
    • pp.605-614
    • /
    • 2010
  • Conventional rolling (symmetric) and differential speed rolling (DSR) were both applied to AA1050 sheets at various velocity ratios, from 1 to 2 between the top and bottom rolls. An electron backscatter diffraction (EBSD) technique was used to measure texture inhomogeneity through the thickness direction. After the annealing process, the annealing texture of the DSR processed sheets was different from that of conventionally rolled sheets. The velocity ratio between the top and bottom rolls affected the texture inhomogeneity and macroscopic plastic strain ratio of the AA1050 sheets. A prediction for the macroscopic plastic strain ratio of AA1050 sheets was carried out using a visco-plastic self-consistent (VPSC) polycrystal model. The strain ratio directionality that was predicted using the VPSC polycrystal model was in good agreement with experimental results.

Elastic-plastic Micromechanics Modeling of Cross-anisotropic Granular Soils: I. Formulation (직교 이방적 사질토의 미시역학적 탄소성 모델링: I. 정식화)

  • Jung, Young-Hoon;Chung, Choong-Ki
    • Journal of the Korean Geotechnical Society
    • /
    • v.23 no.3
    • /
    • pp.77-88
    • /
    • 2007
  • A micromechanics-based model to simulate the elastic and elastic-plastic behavior of granular soils is developed. The model accounts for the fabric anisotropy represented by the statistical parameter of the spatial distribution of contact normals, the evolution of fabric anisotropy as a function of stress ratio, the continuous change of the co-ordination number relating to the void ratio, and the elastic and elastic-plastic microscopic contact stiffness. Using the experimental data for metallic materials, the elastic-plastic contact stiffness is derived as a power function of the normal contact force as well as the contact force initiating the yielding of contact bodies. To quantitatively assess microscopic model parameters, approximate solutions of cross-anisotropic elastic moduli are derived in terms of the micromechanical parameters.