• Title/Summary/Keyword: Matrix Table

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Parameter Identification of 3R-C Equivalent Circuit Model Based on Full Life Cycle Database

  • Che, Yanbo;Jia, Jingjing;Yang, Yuexin;Wang, Shaohui;He, Wei
    • Journal of Electrical Engineering and Technology
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    • v.13 no.4
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    • pp.1759-1768
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    • 2018
  • The energy density, power density and ohm resistance of battery change significantly as results of battery aging, which lead to decrease in the accuracy of the equivalent model. A parameter identification method of the equivale6nt circuit model with 3 R-C branches based on the test database of battery life cycle is proposed in this paper. This database is built on the basis of experiments such as updating of available capacity, charging and discharging tests at different rates and relaxation characteristics tests. It can realize regular update and calibration of key parameters like SOH, so as to ensure the reliability of parameters identified. Taking SOH, SOC and T as independent variables, lookup table method is adopted to set initial value for the parameter matrix. Meanwhile, in order to ensure the validity of the model, the least square method based on variable forgetting factor is adopted for optimizing to complete the identification of equivalent model parameters. By comparing the simulation data with measured data for charging and discharging experiments of Li-ion battery, the effectiveness of the full life cycle database and the model are verified.

Fitting Coefficient Setting Method for the Modified Point Mass Trajectory Model Using CMA-ES (CMA-ES를 활용한 수정질점탄도모델의 탄도수정계수 설정기법)

  • An, Seil;Lee, Kyo Bok;Kang, Tae Hyung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.19 no.1
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    • pp.95-104
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    • 2016
  • To make a firing table of artillery with trajectory simulation, a precise trajectory model which corresponds with real firing test is required. Recent 4-DOF modified point mass trajectory model is considered accurate as a theoretical model, but fitting coefficients are used in calculation to match with real firing test results. In this paper, modified point mass trajectory model is presented and method of setting ballistic coefficient is introduced by applying optimization algorithms. After comparing two different algorithms, Particle Swarm Optimization and Covariance Matrix Adaptation - Evolutionary Strategy, we found that using CMA-ES algorithm gives fine optimization result. This fitting coefficient setting method can be used to make trajectory simulation which is required for development of new projectiles in the future.

FRACTURE BEHAVIOUR OF POSTERIOR COMPOSITE RESINS (구치부(臼齒部) 수복용(修復用) Composite Resin의 파괴거동(破壞擧動)에 관(關)한 연구(硏究))

  • Park, Young-Ho;Min, Byung-Soon;Park, Sang-Jin;Choi, Ho-Young
    • Restorative Dentistry and Endodontics
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    • v.12 no.2
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    • pp.33-44
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    • 1987
  • The use of composite resin for the posterior teeth gives rise to clinical problem due to the lack of mechanical properties. The purpose of this study was to observe the fractured surfaces of light posterior composite resins which are P-10, Clearfil posterior, Adaptic anterior & posterior, P-30, Lite-fil posterior, Estilux posterior, Helio-molar, and Ful-fil com pules (Table 1). The failure of composite resin specimens of I, T and Y-Type (Fig. 1,2) occured under compression. Fractographical observations by SEM (JSM-T20, JEOL) were carried out in order to examine the fracture behaviour of eight composite resins in different types of specimens. The results obtained from this study were as follows: 1. Similar features were found in fractured surfaces of eight composite resins. 2. The crack growth was initiated at the regions of porosities. 3. The crack propagated on the filler-matrix interface. 4. As the crack increased in size, it accelerated to form secondary crack. 5. The fracture behaviour was dependent on the content, size, shape, and distribution of fillers.

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LE analysis on unsaturated slope stability with introduction of nonlinearity of soil strength

  • Deng, Dong-ping;Lu, Kuan;Li, Liang
    • Geomechanics and Engineering
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    • v.19 no.2
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    • pp.179-191
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    • 2019
  • Based on the effective stress principle, a new formula for shear strength of unsaturated soil is derived under the general nonlinear Mohr-Coulomb (M-C) strength criterion to improve the classical strength criterion of unsaturated soil. Meanwhile, the simple irrigation model under steady seepage is adopted to obtain the distribution of the matrix suction or the degree of saturation (DOS) above the groundwater table in the slope. Then, combined with the improved strength criterion of unsaturated soil and the simple irrigation model under steady seepage, the limit equilibrium (LE) solutions for the unsaturated slope stability are established according to the global LE conditions of the entire sliding body with assumption of the stresses on the slip surface. Compared to the classical strength criterion of unsaturated soil, not only the cohesion soil but also the internal friction angle is affected by the matric suction or the DOS in the improved strength criterion. Moreover, the internal friction angle related to the matric suction has the nonlinear characteristics, particularly for a small of the matric suction. Thereafter, the feasibility of the present method is verified by comparison and analysis on some slope examples. Furthermore, stability charts are also drawn to quickly analyze the unsaturated slope stability.

The Study of Educational Program Development for Self-Marketing based on Job Analysis

  • Ahn, Sang Joon
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.9
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    • pp.135-142
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    • 2019
  • Given the ability and skills required by modern people, marketing can be divided into knowledge-related skill such as marketing plans, market segmentation, and marketing mix management and supportive skill such as communication, inter-organizational management, creativity, and decision making. Knowledge related skills can be nurtured in existing marketing classes, but it is recognized that special educational programs such as self marketing are needed to develop and train supportive skills regardless of education levels or major education. This paper is aimed to design for marketing educational program for the self marketing. In this study, a DACUM method job analysis to extract contents by specialists such as model setting of task and job, job statement, job analysis, education course development, and so on. In the first place, this report presents job analysis model by procedures for developing selection criteria of examination questions of the self marketing qualification. The first step is preparation for job analysis, the second step: the establishment of job models, the third step : the job specification and task analysis, the fourth step: the review of job model, the fifth step: the establishment of subjects for examination matrix table for making questions.

An improved Kalman filter for joint estimation of structural states and unknown loadings

  • He, Jia;Zhang, Xiaoxiong;Dai, Naxin
    • Smart Structures and Systems
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    • v.24 no.2
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    • pp.209-221
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    • 2019
  • The classical Kalman filter (KF) provides a practical and efficient way for state estimation. It is, however, not applicable when the external excitations applied to the structures are unknown. Moreover, it is known the classical KF is only suitable for linear systems and can't handle the nonlinear cases. The aim of this paper is to extend the classical KF approach to circumvent the aforementioned limitations for the joint estimation of structural states and the unknown inputs. On the basis of the scheme of the classical KF, analytical recursive solution of an improved KF approach is derived and presented. A revised form of observation equation is obtained basing on a projection matrix. The structural states and the unknown inputs are then simultaneously estimated with limited measurements in linear or nonlinear systems. The efficiency and accuracy of the proposed approach is verified via a five-story shear building, a simply supported beam, and three sorts of nonlinear hysteretic structures. The shaking table tests of a five-story building structure are also employed for the validation of the robustness of the proposed approach. Numerical and experimental results show that the proposed approach can not only satisfactorily estimate structural states, but also identify unknown loadings with acceptable accuracy for both linear and nonlinear systems.

School Consulting Model to Establish the Development Plan of Industrial High School and a Case Analysis (공업계열 고등학교의 발전계획 수립을 위한 학교컨설팅 모델 및 사례 분석)

  • Kim, Jinsoo
    • 대한공업교육학회지
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    • v.33 no.2
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    • pp.1-25
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    • 2008
  • In this study, theory of school consulting for founding the development strategy of industrial high school was explored, consulting model and performing technique model was suggested, case of consulting of industrial high school performed by the model and performing technique suggested. Up to now, research field of school consulting was instruction and supervision consulting mostly, there was not much school management consulting. In this paper, a school consulting model for industrial high school was developed, which was five step such as entry, diagnosis, action planning, action, and termination. A case of consulting for C technical high school applied by the consulting model suggested was analyzed, it will be used any other consulting project of industrial high school. According to the 5 step school consulting model, analysis of the present state of C technical high school, survey research, SWOT analysis, Issue Tree, school assesment were performed. In order to set up a development strategy for C technical high school, a table of problem and improvement based on issue tree was made, and then a Pay-Off Matrix was made out. Finally, a development plan of short and mid- and long-term for C technical high school was constructed.

Analysis of Image Distortion on Magnetic Resonance Diffusion Weighted Imaging

  • Cho, Ah Rang;Lee, Hae Kag;Yoo, Heung Joon;Park, Cheol-Soo
    • Journal of Magnetics
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    • v.20 no.4
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    • pp.381-386
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    • 2015
  • The purpose of this study is to improve diagnostic efficiency of clinical study by setting up guidelines for more precise examination with a comparative analysis of signal intensity and image distortion depending on the location of X axial of object when performing magnetic resonance diffusion weighted imaging (MR DWI) examination. We arranged the self-produced phantom with a 45 mm of interval from the core of 44 regent bottles that have a 16 mm of external diameter and 55 mm of height, and were placed in 4 rows and 11 columns in an acrylic box. We also filled up water and margarine to portrait the fat. We used 3T Skyra and 18 Channel Body array coil. We also obtained the coronal image with the direction of RL (right to left) by using scan slice thinkness 3 mm, slice gap: 0mm, field of view (FOV): $450{\times}450mm^2$, repetition time (TR): 5000 ms, echo time (TE): 73/118 ms, Matrix: $126{\times}126$, slice number: 15, scan time: 9 min 45sec, number of excitations (NEX): 3, phase encoding as a diffusion-weighted imaging parameter. In order to scan, we set b-value to $0s/mm^2$, $400s/mm^2$, and $1,400s/mm^2$, and obtained T2 fat saturation image. Then we did a comparative analysis on the differences between image distortion and signal intensity depending on the location of X axial based on iso-center of patient's table. We used "Image J" as a comparative analysis programme, and used SPSS v18.0 as a statistic programme. There was not much difference between image distortion and signal intensity on fat and water from T2 fat saturation image. But, the average value depends on the location of X axial was statistically significant (p < 0.05). From DWI image, when b-value was 0 and 400, there was no significant difference up to $2^{nd}$ columns right to left from the core of patient's table, however, there was a decline in signal intensity and image distortion from the $3^{rd}$ columns and they started to decrease rapidly at the $4^{th}$ columns. When b-value was 1,400, there was not much difference between the $1^{st}$ row right to left from the core of patient's table, however, image distortion started to appear from the $2^{nd}$ columns with no change in signal intensity, the signal was getting decreased from the $3^{rd}$ columns, and both signal intensity and image distortion started to get decreased rapidly. At this moment, the reagent bottles from outside out of 11 reagent bottles were not verified from the image, and only 9 reagent bottles were verified. However, it was not possible to verify anything from the $5^{th}$ columns. But, the average value depends on the location of X axial was statistically significant. On T2 FS image, there was a significant decline in image distortion and signal intensity over 180mm from the core of patient's table. On diffusion-weighted image, there was a significant decline in image distortion and signal intensity over 90 mm, and they became unverifiable over 180 mm. Therefore, we should make an image that has a diagnostic value from examinations that are hard to locate patient's position.

Improvement of analytical method for pymetrozine in citrus fruits (감귤류 과일의 피메트로진 정량을 위한 분석법 개선)

  • Jeon, Jun-Ho;Chun, Su-Hyun;Kim, Min-Hyuk;Kim, Mi-Ok;Lee, Kwang-Won
    • Korean Journal of Food Science and Technology
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    • v.51 no.4
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    • pp.316-323
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    • 2019
  • It is difficult to analyze pymetrozine in citrus fruits using the hydromatrix method because of its low efficiency of purification and overlap of matrix and pymetrozine peaks. Liquid-liquid extraction can analyze pymetrozine in citrus fruits using dichloromethane. Since low pH interferes with the extraction of pymetrozine, the extracts of citrus fruits were maintained over pH 7.0 by adding borax buffer and 1 N NaOH in the improved method. According to the improved method, citrus fruits (such as lemon, lime, orange, tangerine, and grapefruit) were extracted and purified for HPLC-photo diode array analysis. The results of validation were as follows: $4.360{\mu}g/kg$ of limit of detection, $14.533{\mu}g/kg$ of limit of quantitation, and 0.007 mg/kg of method quantitative limit. Citrus fruits spiked with pymetrozine showed a recovery range from 71.8 to 83.7% and a coefficient of variation below 6%. Thus, the improved method can efficiently analyze pymetrozine in citrus fruits.

Technological Synergy Effect of Business Portfolio : Panel Data Analysis on 50 Largest Chaebols in Korea (사업포트폴리오의 기술시너지효과 :50대 재벌의 패널자료분석)

  • 김태유;박경민
    • Proceedings of the Technology Innovation Conference
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    • 1996.12a
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    • pp.265-295
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    • 1996
  • This paper investigates empirically the relationship between various business portfolio properties (particularly technological properties) and chaebol′s performance using data on the 50 largest chaebols in Korea. In addition to the traditional indexes to measure diversification such as entropy index we calculated inter-industry technological similarity using R&D expenditure data by industry and 1990 Input-output Table in Korea, and obtained chaebol-level technological relatedness and internal transaction proportion from chaebols′business profile, inter-industry technological similarity and 1990 input-output table. We applied factor analysis on 13 business portfolio property indexes and showed that they could be grouped into 3 dimensions, diversification scope, inter-business relatedness and degree of vertical integration. In this paper, using 50 largest chaebols′financial data (1989-1994), we analyzed empirically the effect of business portfolio properties on ROS (Return On Sales) which is conventional index for firm performance and on TFP(Total Factor Productivity) growth which is a pure measure of firm performance. To utilize the advantage of panel data, FEM(Fixed Effect Model) and REM(Random Effect Model) were used. The empirical result shows that the entropy index as a measurement of inter-business relatedness is not significant but technological relatedness index is significant. OLS estimates on pooled data were considerably different from FEM or REM estimates on panel data. By introducing interaction effect among the three variables for business portfolio properties, we obtained three findings. First, only VI (Vertical integration) has a significant positive correlation with ROS. Second, when using TFP growth as an dependent variable, both TR(Technological Relatedness) and f[ are significant and positively related to the deepened variable. Third, the interaction term between TR and VI is significant and negatively affects TFP growth, meaning that TR and VI are substitutes. These results suggest strategic directions on restructuring business portfolio. As VI is increased, chaebols will get more profit. A higher level of either TR or W will increase TFP growth rate. but increase in both TR and VI will have a negative effect on TFP growth. To summarize, certain business portfolio properties such as VI and TR can be considered "resources" themselves since they can affect profit rate and productivity growth. VI and TR have a synergy effect of change in profit rate and productivity growth. VI increases ROS and productivity growth, while TR increases productivity growth representing a technological synergy effect.

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