• Title/Summary/Keyword: Quantitative parameter

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Lattice based Microstructure Evolution Model for Monte Carlo Finite Element Analysis of Polycrystalline Materials (격자식 미세구조 성장 모델을 이용한 다결정 박막 소재의 유한 요소 해석)

  • 최재환;김한성;이준기;나경환
    • Transactions of Materials Processing
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    • v.13 no.3
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    • pp.248-252
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    • 2004
  • The mechanical properties of polycrystalline thin-films, critical for Micro-Electro-Mechanical Systems (MEMS) components, are known to have the size effect and the scatter in the length scale of microns by the numbers of intensive investigation by experiments and simulations. So, the consideration of the microstructure is essential to cover these length scale effects. The lattice based stochastic model for the microstructure evolution is used to simulate the actual microstructure, and the fast and reliable algorithm is described in this paper. The kinetics parameters, which are the key parameters for the microstructure evolution based on the nucleation and growth mechanism, are extracted from the given micrograph of a polycrystalline material by an inverse method. And the method is verified by the comparison of the quantitative measures, the number of grains and the grain size distribution, for the actual and simulated microstructures. Finite element mesh is then generated on this lattice based microstructure by the developed code. And the statistical finite element analysis is accomplished for selected microstructure.

Ultrasound Image Diagnosis using Texture Analysis (TEXTURE 분석을 이용한 초음파 화상의 진단)

  • Choi, Kwang-Cheol;Kim, Sun-Il;Lee, Doo-Soo
    • Journal of Biomedical Engineering Research
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    • v.13 no.1
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    • pp.33-38
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    • 1992
  • A new approach to texture classification for quantitative ultrasound liver diagnosis using run difference matrix was developed. The run difference matrix comprised the gray level difference along with a distances. From this run difference matrix, we defined several vectors and parameters such as DOD, DGD, DAD vector, SHP, SMO, SMG, LDE, LDEL etc. Each parameter values calculated in fatty, cirrhotic, normal and chronic hepatitic liver images were plotted in a plane and we found that RDM method was more sensitive to small structural changes than the conventional run length method and showed improved classification ability between the diseases.

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Evaluation System of Psychological Feelings for Corporate Identity Symbol Marks Using Fuzzy Neural Networks (퍼지 - 뉴럴네트워크를 이용한 CI 심벌마크의 감성평가시스템)

  • Chang, In-Seong;Park, Yong-Ju
    • Journal of Korean Institute of Industrial Engineers
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    • v.27 no.3
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    • pp.305-314
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    • 2001
  • In this paper, we construct an automatic evaluation system of psychological feeling for corporate identity (CI) symbol mark based on a fuzzy neural network technique. The system is modelled by trainable fuzzy inference rules with several input variables (qualitative and quantitative design components of CI symbol mark) and a single output variable (consumer's feeling). The back propagation learning algorithm, which is a conventional learning method of multilayer feedforward neural networks, is used for parameter identification of the fuzzy inference system. The learning ability to train data and the generalization ability to test data are evaluated for the proposed evaluation system by computer simulations.

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Thermal Dissipation Characteristics of Multi-Chip LED Packages (멀티 칩 LED 패키지의 방열 특성)

  • Kim, Byung-Ho;Moon, Cheol-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.12
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    • pp.34-41
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    • 2011
  • In order to understand the thermal performance of each LED chips in multi-chip LED package, a quantitative parametric analysis of the temperature evolution was investigated by thermal transient analysis. TSP (Temperature Sensitive Parameter) value was measured and the junction temperature was predicted. Thermal resistance between the p-n junction and the ambient was obtained from the structure function with the junction temperature evolution during the cooling period of LED. The results showed that, the thermal resistance of the each LED chips in 4 chip-LED package was higher than that of single chip- LED package.

Windborne debris and damage risk models: a review

  • Holmes, J.D.
    • Wind and Structures
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    • v.13 no.2
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    • pp.95-108
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    • 2010
  • This review paper discusses research from the last few years relating to windborne debris risk models and the essential elements of engineering damage prediction models. Generic types of windborne debris are discussed. The results of studies of debris trajectories that are relevant to damage models are described - in particular the horizontal component of debris velocity as a function of distance travelled. The merits of impact momentum versus impact kinetic energy as a relevant parameter for predicting damage are considered, and how published data from generic cannon Impact tests can be used in risk models. The quantitative variation of debris impact damage with wind speed is also discussed. Finally the main elements of previously-proposed debris damage models are described.

Solidification Analysis of Steel Castings & Large Ingots By Modified Finite Difference Method (개량차분법에 의한 주강품 및 대형 잉곳드의 응고해석과 수축공 예측)

  • Lee, Young-Chul;Kim, Jong-Won;Hong, Chun-Pyo
    • Journal of Korea Foundry Society
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    • v.9 no.1
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    • pp.67-72
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    • 1989
  • Solidification analysis was conducted on large steel castings and ingots by a modified finite difference method. Auto-mesh generation system was developed for improving the application of the computer analysis system to casting disign. Combined use of the prediction parameters, solidification time and temperature gradient, and an auxiliary parameter, shrinkage potential, were used to predict the formation of shrinkage defects. Several examples on the prediction of shrinkage cavity by this method were campared with the experimental reslts. It was found that a quantitative design of large steel castings and ingots can be made by the computer aided analysis of solidification process.

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Calculation of electric field gradient tensor for simple point charge distributions and its application to real systems

  • Choh, Sung-Ho;Shin, Hee-Won;Park, II-Woo;Ju, Heong-Kyu;Kim, Jong-Hyun;Kim, Hae-Jin
    • Journal of the Korean Magnetic Resonance Society
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    • v.7 no.1
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    • pp.16-24
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    • 2003
  • Nuclei with the spin quantum number not smaller than unity have not only the nuclear magnetic moment but also the electric quadrupole moment. The quadrupole moment couples with the electric field gradient (EFG) to produce the nuclear quadrupole interaction. It is well known that two independent parameters, i.e. the quadrupole coupling constant (QCC) and the asymmetry parameter ($\eta$) together with the principal axis directions can fully describe the interaction and are very sensitive to the local symmetry and structure of the solid. In order to obtain quantitative estimates of the EFG tensor for various simple ionic configurations surrounding the nucleus under consideration, we employ the simple point charge approximation and apply the calculated results to some real crystals. General agreement is rather satisfactory.

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Skin Wrinkle Detection Using Dermatologic Magnifier Based on Variable Polarization and Optical Magnification (가변편광과 광학배율을 기반으로 한 피부 확대경을 이용한 피부주름 측정)

  • Bae, Young-Woo;Jung, Byung-Jo
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.190-192
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    • 2006
  • The clinical characteristics of photodamaged skin, such as coarse and fine wrinkle are not accurately evaluable with previous methods. Public awareness for wrinkle treatment and prevention which rely on proper assessment and evaluation of the underlying skin changes has been increased as the population ages. In this paper, we suggest an in-vivo method and instrument that allow us to acquire a wrinkle-enhanced image to improve the accuracy of quantitative and qualitative analysis for skin wrinkle. The method used involved white LED illumination and photography through polarizing filters. Finally, the polarized light photography yields an accurate and evaluable parameter of photodamaged skin, especially fine and coarse wrinkle.

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Hologram Based QSAR Analysis of Xanthine Oxidase Inhibitors

  • Sathya., B
    • Journal of Integrative Natural Science
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    • v.10 no.4
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    • pp.202-208
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    • 2017
  • Xanthine Oxidase is an enzyme, which oxidizes hypoxanthine to xanthine, and xanthine to uric acid. It is widely distributed throughout various organs including the liver, gut, lungs, kidney, heart, brain and plasma. It is involved in gout pathogenesis. Hence, in the present study, Hologram based Quantitative Structure Activity Relationship Study was performed on a series of Xanthine Oxidase antagonist named 2-(indol-5-yl) thiazole derivatives. The best HQSAR model was obtained using Atoms, Bonds, Connection, Hydrogen, Chirality and Donor Acceptor as fragment distinction parameter using hologram length 71 and 4 components with fragment size of minimum 2 and maximum 5. Significant cross-validated correlation coefficient ($q^2$= 0.563) and non cross-validated correlation coefficients ($r^2$= 0.967) were obtained. The model was then used to evaluate the six external test compounds and its $r^2{_{pred}}$ was found to be 0.798. Contribution map show that presence of propyl ring in indole thiazole makes big contributions for improving the biological activities of the compounds. We hope that our HQSAR model and analysis will be helpful for future design of xanthine oxidase antagonists.

Analysis of Shape Distribution Characteristics of Wear Particles using Histogram (도수분포를 이용한 마멸입자의 형태 분포특성의 분석)

  • Park, Heung-Sik;Woo, Kyu-Sung;Cho, Yon-Sang;Jun, Sung-Jae
    • Tribology and Lubricants
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    • v.23 no.1
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    • pp.29-36
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    • 2007
  • It necessarily follows that wear particles are generated through a friction and wear in a mechanical moving system. The wear particles are relative to the failure and the life of machine elements directly. To analyze the wear particle, its shape characteristics were calculated quantitative values such as diameter, roundness and fractal parameters by digital image processing. In this study, the histograms of shape parameters of wear particles were used for the purpose of analyzing the distribution of wear particles in various conditions. We consider that the histogram of shape parameter can be effectively represented to study a wear mechanism.