• Title/Summary/Keyword: Coefficient Selection

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The Effect on the Dietary Habits and Food Purchase Type according to the Stress in Chinese Students (경기지역 중국인 유학생의 스트레스가 식습관 및 식품구매 형태에 미치는 영향)

  • Jang, Jae-Seon
    • The Korean Journal of Food And Nutrition
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    • v.32 no.3
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    • pp.267-274
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    • 2019
  • This study was performed to provide fundamental data on the dietary habits and food purchase types according to the stress patterns. The subject was 312 Chinese students in Gyeonggi region through a self-administered questionnaire. According to the results of the reliability analysis, the stress items showed an average of 2.91 and 0.846 for Cronbach alpha coefficient. The results of ANOVA analysis on the difference of dietary habits according to stress are as follows; There were significant differences for the meal frequency per day according to schoolwork, economic, general living, and dietary habits (p<0.05). Also, the general living pattern showed significant differences for the meal outside frequency and Chinese food intake (p<0.05). The results of ANOVA analysis on the difference of food purchase type according to stress are as follows; There was significant differences in degree of use of convenience foods according to interpersonal relationship, cooking method of convenience foods according to economics, the selection criteria of convenience foods according to schoolwork (p<0.05). The correlation coefficient of dietary habits and convenience food intake are 0.223, -0.147 in stress degree and dietary habits. In conclusion, I would like to provide the basic data necessary for the right choice of Chinese students' dietary habits and food purchases.

Hopf Bifurcation Study of Inductively Coupled Power Transfer Systems Based on SS-type Compensation

  • Xia, Chenyang;Yang, Ying;Peng, Yuxiang;Hu, Aiguo Patrick
    • Journal of Power Electronics
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    • v.19 no.3
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    • pp.655-664
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    • 2019
  • In order to analyze the nonlinear phenomena of the bifurcation and chaos caused by the switching of nonlinear switching devices in inductively coupled power transfer (ICPT) systems, a Jacobian matrix model, based on discrete mapping numerical modeling, is established to judge the system stability of the periodic closed orbit and to study the nonlinear behavior of Hopf bifurcation in a system under full resonance. The general flow of the parameter design, based on the stability principle for ICPT systems, is proposed to avoid the chaos and bifurcation phenomena caused by unreasonable parameter selection. Firstly, based on the state equation of SS-type compensation, a three-dimensional bifurcation diagram with the coupling coefficient as the bifurcation parameter is established with a numerical simulation to observe the nonlinear phenomena in the system. Then Filippov's method based on a Jacobian matrix model is adopted to deduce the boundary of stable operation and to judge the type of the bifurcation in the system. Then the general flow of the parameter design based on the stability principle for ICPT systems is proposed through the above analysis to realize stable operation under the conditions of weak coupling. Finally, an experimental platform is built to confirm the correctness of the numerical simulation and modeling.

Bond strength prediction of spliced GFRP bars in concrete beams using soft computing methods

  • Shahri, Saeed Farahi;Mousavi, Seyed Roohollah
    • Computers and Concrete
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    • v.27 no.4
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    • pp.305-317
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    • 2021
  • The bond between the concrete and bar is a main factor affecting the performance of the reinforced concrete (RC) members, and since the steel corrosion reduces the bond strength, studying the bond behavior of concrete and GFRP bars is quite necessary. In this research, a database including 112 concrete beam test specimens reinforced with spliced GFRP bars in the splitting failure mode has been collected and used to estimate the concrete-GFRP bar bond strength. This paper aims to accurately estimate the bond strength of spliced GFRP bars in concrete beams by applying three soft computing models including multivariate adaptive regression spline (MARS), Kriging, and M5 model tree. Since the selection of regularization parameters greatly affects the fitting of MARS, Kriging, and M5 models, the regularization parameters have been so optimized as to maximize the training data convergence coefficient. Three hybrid model coupling soft computing methods and genetic algorithm is proposed to automatically perform the trial and error process for finding appropriate modeling regularization parameters. Results have shown that proposed models have significantly increased the prediction accuracy compared to previous models. The proposed MARS, Kriging, and M5 models have improved the convergence coefficient by about 65, 63 and 49%, respectively, compared to the best previous model.

RAPD Polymorphism and Genetic Distance among Phenotypic Variants of Tamarindus indica

  • Mayavel, A;Vikashini, B;Bhuvanam, S;Shanthi, A;Kamalakannan, R;Kim, Ki-Won;Kang, Kyu-Suk
    • Journal of Korean Society of Forest Science
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    • v.109 no.4
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    • pp.421-428
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    • 2020
  • Tamarind (Tamarindus indica L.) is one of the multipurpose tree species distributed in the tropical and sub-tropical climates. It is an important fruit yielding tree that supports the livelihood and has high social and cultural values for rural communities. The vegetative, reproductive, qualitative, and quantitative traits of tamarind vary widely. Characterization of phenotypic and genetic structure is essential for the selection of suitable accessions for sustainable cultivation and conservation. This study aimedto examine the genetic relationship among the collected accessions of sweet, red, and sour tamarind by using Random Amplified Polymorphic DNA (RAPD) primers. Nine accessions were collected from germplasm gene banks and subjected to marker analysis. Fifteen highly polymorphic primers generated a total of 169 fragments, out of which 138 bands were polymorphic. The polymorphic information content of RAPD markers varied from 0.10 to 0.44, and the Jaccard's similarity coefficient values ranged from 0.37 to 0.70. The genetic clustering showed a sizable genetic variation in the tamarind accessions at the molecular level. The molecular and biochemical variations in the selected accessions are very important for developing varieties with high sugar, anthocyanin, and acidity traits in the ongoing tamarind improvement program.

A Comparative Study of Software Reliability Model Considering Log Type Mean Value Function (로그형 평균값함수를 고려한 소프트웨어 신뢰성모형에 대한 비교연구)

  • Shin, Hyun Cheul;Kim, Hee Cheul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.10 no.4
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    • pp.19-27
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    • 2014
  • Software reliability in the software development process is an important issue. Software process improvement helps in finishing with reliable software product. Infinite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, proposes the reliability model with log type mean value function (Musa-Okumoto and log power model), which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination($R^2$), for the sake of efficient model, was employed. Analysis of failure using real data set for the sake of proposing log type mean value function was employed. This analysis of failure data compared with log type mean value function. In order to insurance for the reliability of data, Laplace trend test was employed. In this study, the log type model is also efficient in terms of reliability because it (the coefficient of determination is 70% or more) in the field of the conventional model can be used as an alternative could be confirmed. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can be able to help.

Comparison of the effects of irradiation on iso-molded, fine grain nuclear graphites: ETU-10, IG-110 and NBG-25

  • Chi, Se-Hwan
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2359-2366
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    • 2022
  • Selecting graphite grades with superior irradiation characteristics is important task for designers of graphite moderation reactors. To provide reference information and data for graphite selection, the effects of irradiation on three fine-grained, iso-molded nuclear grade graphites, ETU-10, IG-110, and NBG-25, were compared based on irradiation-induced changes in volume, thermal conductivity, dynamic Young's modulus, and coefficient of thermal expansion. Data employed in this study were obtained from reported irradiation test results in the high flux isotope reactor (HFIR)(ORNL) (ETU-10, IG-110) and high flux reactor (HFR)(NRL) (IG-110, NBG-25). Comparisons were made based on the irradiation dose and irradiation temperature. Overall, the three grades showed similar irradiation-induced property change behaviors, which followed the historic data. More or less grade-sensitive behaviors were observed for the changes in volume and thermal conductivity, and, in contrast, grade-insensitive behaviors were observed for dynamic Young's modulus and coefficient of thermal expansion changes. The ETU-10 of the smallest grain size appeared to show a relatively smaller VC to IG-110 and NBG-25. Drastic decrease in the difference in thermal conductivity was observed for ETU-10 and IG-110 after irradiation. The similar irradiation-induced properties changing behaviors observed in this study especially in the DYM and CTE may be attributed to the assumed similar microstructures that evolved from the similar size coke particles and the same forming method.

Selection of Varieties with Higher Cultural Stability in Sesamum indicum (재배적 안정성이 높은 참깨 계통 선발)

  • Shim, Kang-Bo;Kang, Chul-Whan;Lee, Sung-Woo;Kim, Dong-Hee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.45 no.6
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    • pp.374-381
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    • 2000
  • This study was conducted to select sesame varieties with high cultural stabilities by comparing several parameters of agronomic traits under the different cultural environments. Of the six areas, Iksan and Jinju areas which showed positively larger environment index values were relatively adequate cultural conditions for sesame. At the comparison of cultural stability of agronomic traits by Eberhart and Russell regression model among sesame breeding lines, Suwon 169 showed more stable regression coefficient values to the number of capsules per plant, number of seeds per capsule and seed weight per plant, and Iksan 12 showed more stable regression coefficient values to culm length and weight per plant. At the comparison of cultural stability of yield per 10a, Suwon 169 and Iksan 12 among sesame breeding lines showed more stable respectively, deviation values of 0.99, 0.98 respectively, and more less regression deviation values of 0.074, 0.167 respectively. Therefore those breeding lines are comparatively higher stabilities to yield determining agronomic traits under the different cultural environments, and it was concluded that those two breeding lines had the possibility to recommend promising breeding lines in the future.

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Geotechnical problems in flexible pavement structures design

  • Mato G. Uljarevic;Snjezana Z. Milovanovic;Radovan B. Vukomanovic;Dragana D. Zeljic
    • Geomechanics and Engineering
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    • v.32 no.1
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    • pp.35-47
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    • 2023
  • Deformability of road pavements in the form of ruts represent a safety risk for road users. In the procedures for dimensioning the pavement structure, the requirement that such deformations do not occur is imperatively included, which results in the appropriate selection of elements (material, geometry) of the pavement structure. Deformability and functionality, will depend of the correct design of pavement structure during exploitation period. Nevertheless, there are many examples where deformations are observed on the pavement structure, in the form of rutting at parts of the road with relatively short length, realised in the same climatic and the same geoenvironmental conditions. The performed analysis of deformability led to the conclusion that the level of deformation is a function of the speed of traffic. This effect is observed on city roads, but also outside of urban areas at roads with speed limits are significant, due to the traffic management, traffic jams (intersections, etc.). Still, the lower speed cause greater deformations. The authors tried to describe the deformability of flexible pavement structures, from the aspects of geotechnical problems, as a function of driving speed. Outcome of the analysis is a traffic load correction coefficient, in terms of using the existing methods of flexible pavement structures design.

Analysis of underground post-tensioned precast concrete box utility tunnel under normal fault displacement

  • Wu, Xiangguo;Nie, Chenhang;Qiu, Faqiang;Zhang, Xuesen;Hong, Li;Lee, Jong-Sub;Kang, Thomas H.K.
    • Computers and Concrete
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    • v.29 no.2
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    • pp.69-79
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    • 2022
  • For long underground box utility tunnels, post-tensioned precast concrete is often used. Between precast tunnel segments, sealed waterproof flexible joints are often specified. Fault displacement can lead to excessive deformation of the joints, which can lead to reduction in waterproofing due to diminished contact pressure between the sealant strip and the tunnel segment. This paper authenticates utilization of a finite element model for a prefabricated tunnel fault-crossing founded on ABAQUS software. In addition, material parameter selection, contact setting and boundary condition are reviewed. Analyzed under normal fault action are: the influence of fault displacement; buried depth; soil friction coefficient, and angle of crossing at the fault plane. In addition, distribution characteristics of the utility tunnel structure for vertical and longitudinal/horizontal relative displacement at segmented interface for the top and bottom slab are analyzed. It is found that the effect of increase in fault displacement on the splice joint deformation is significant, whereas the effects of changes in burial depth, pipe-soil friction coefficient and fault-crossing angle on the overall tunnel and joint deformations were not so significant.

Research on the Applicability of Target-detection Methods for Land-based Hyperspectral Imaging

  • Qianghui Wang;Bing Zhou;Wenshen Hua;Jiaju Ying;Xun Liu;Lei Deng
    • Current Optics and Photonics
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    • v.8 no.3
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    • pp.282-299
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    • 2024
  • Target detection (TD) is a research hotspot in the field of hyperspectral imaging (HSI). Traditional TD methods often mine targets from HSIs under a single imaging condition, without considering the influence of imaging conditions. In fact, the spectra of ground objects in HSIs are uncertain and affected by the imaging conditions (weather, atmospheric, light, time, and other angle conditions including zenith angle). Hyperspectral data changes under different imaging conditions. Therefore, the detection result for a single imaging condition cannot accurately reflect the effectiveness of the detection method used. It is necessary to analyze the performance of various detection methods under different imaging conditions, to find a more applicable detection method. In this paper, we study the performance of TD methods under various land-based imaging conditions. We first summarize classical TD methods and evaluation methods. Then, the detection effects under various imaging conditions are analyzed. Finally, the concepts of the stability coefficient (SC) and effective area under the curve (EAUC) are proposed to comprehensively evaluate the applicability of detection methods under land-based imaging conditions, in terms of both detection accuracy and stability. This is conducive to our selection of detection methods with better applicability in land-based contexts, to improve detection accuracy and stability.