• Title/Summary/Keyword: field-consistency

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A comparative study of different radial basis function interpolation algorithms in the reconstruction and path planning of γ radiation fields

  • Yulong Zhang;Jinjia Cao;Biao Zhang;Xiaochang Zheng;Wei Chen
    • Nuclear Engineering and Technology
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    • v.56 no.7
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    • pp.2806-2820
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    • 2024
  • Accurate reconstruction of radiation field and path planning are very important for the safety of operators in the process of dismantling nuclear facilities. Based on radial basis function (RBF) interpolation algorithm, this paper discussed the application of inverse multiquadric radial basis Function (IMRBF) interpolation method to the reconstruction of gamma radiation field, and proved the feasibility of reconstructing a radiation field with multiple γ sources. The average relative errors of IMRBF interpolation results were 4.28% and 8.76%, respectively, for the experimental scenarios with single and double gamma sources. After comparing the consistency between the simulated scene and the experimental scene, IMRBF method and Cubic Spline method were respectively used to reconstruct the gamma radiation field by Geant4 simulation data. The results showed that the interpolation accuracy of IMRBF method was superior to that of Cubic Spline method. Further, more RBF interpolation algorithms were used to reconstruct the multi-γ source radiation field, and then the Probabilistic Roadmap (PRM) algorithm was used to optimize the human walking path in the radiation field reconstructed by different interpolation methods. The optimal paths in radiation fields generated by multiple interpolation methods were compared. The results herein contribute to a comprehensive understanding of RBF interpolation methods in reconstructing γ radiation fields and their application in optimizing paths in radiation environments. The insights may provide valuable information for decision-making in radiation protection during the decommissioning of nuclear facilities.

A Study on Factors Influencing to Coefficient of Consolidation in Horizontal Direction (수평압밀계수의 영향인자에 관한 연구)

  • Kim, Chang-Seop;Park, Byung-Soo;Yoo, Nam-Jae
    • Journal of Industrial Technology
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    • v.28 no.B
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    • pp.81-89
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    • 2008
  • This paper is results of investigating the dominant factors influencing to coefficient of consolidation in horizontal direction of Korean marine clays and their correlations through literature review. From the results of analyzing data obtained from field tests such as piezocone penetration and dilatometer tests as well as laboratory tests, coefficient of consolidation in the horizontal direction was found to increase with increase of stiffness index of soil while it decreases with the increase of dissipation time of pore pressure developed during field tests. In general, the coefficient of consolidation in the horizontal direction tends to increase with increase of undrained shear strength and preconsolidation pressure although correlation between them are relatively low. Friction ratio has a high correlation with coefficient of consolidation in the horizontal direction in case of friction ratio being greater than 1.0. For methods of estimating coefficient of consolidation in the horizontal direction with different testing device, values obtained from methods of P2-logt and DMT-A with dilatometer were quite similar to values from piezocone penetration test. Consistency of soil is quite proportional to coefficient of consolidation in the horizontal direction. Clear correlation between coefficients of consolidation in the horizontal and the vertical directions could not be found. coefficient of consolidation in the horizontal direction estimated from the results of field test tends to be 1.13~3.11 times greater than that obtained from laboratory tests.

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Narrow Resonant Double-Ridged Rectangular Waveguide Probe for Near-Field Scanning Microwave Microscopy

  • Kim, Byung-Mun;Son, Hyeok-Woo;Cho, Young-Ki
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.406-412
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    • 2018
  • In this paper, we propose a narrow resonant waveguide probe that can improve the measurement sensitivity in near-field scanning microwave microscopy. The probe consists of a metal waveguide incorporating the following two sections: a straight section at the tip of the probe whose cross-section is a double-ridged rectangle, and whose height is much smaller than the waveguide width; and a standard waveguide section. The advantage of the narrow waveguide is the same as that of the quarter-wave transformer section i.e., it achieves impedance-matching between the sample under test (SUT) and the standard waveguide. The design procedure used for the probe is presented in detail and the performance of the designed resonant probe is evaluated theoretically by using an equivalent circuit. The calculated results are compared with those obtained using the finite element method (Ansoft HFSS), and consistency between the results is demonstrated. Furthermore, the performance of the fabricated resonant probe is evaluated experimentally. At X-band frequencies, we have measured the one-dimensional scanning reflection coefficient of the SUT using the probe. The sensitivity of the proposed resonant probe is improved by more than two times as compared to a conventional waveguide cavity type probe.

Mesh distortion, locking and the use of metric trial functions for displacement type finite elements

  • Kumar, Surendra;Prathap, G.
    • Structural Engineering and Mechanics
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    • v.29 no.3
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    • pp.289-300
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    • 2008
  • The use of metric trial functions to represent the real stress field in what is called the unsymmetric finite element formulation is an effective way to improve predictions from distorted finite elements. This approach works surprisingly well because the use of parametric functions for the test functions satisfies the continuity conditions while the use of metric (Cartesian) shape functions for the trial functions attempts to ensure that the stress representation during finite element computation can retrieve in a best-fit manner, the actual variation of stress in the metric space. However, the issue of how to handle situations where there is locking along with mesh distortion has never been addressed. In this paper, we show that the use of a consistent definition of the constrained strain field in the metric space can ensure a lock-free solution even when there is mesh distortion. The three-noded Timoshenko beam element is used to illustrate the principles. Some significant conclusions are drawn regarding the optimal strategy for finite element modelling where distortion effects and field-consistency requirements have to be reconciled simultaneously.

Analysis of Soil Properties in a Rice Field Using Small Loop EM Method (소형루프 전자탐사에 의한 논 토양분석)

  • Yong Hwan-Ho;Song Sung-Ho;Kim Jin-Ho;Cho In-Ky
    • Geophysics and Geophysical Exploration
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    • v.6 no.4
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    • pp.207-214
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    • 2003
  • To analyze soil properties with depth in rice field, we compared resistivity distributions obtained from soil analysis with one dimensional inversion of small loop electromagnetic (EM) data. Although it didn't show consistency exactly between the two resistivity distributions, low resistivity zones in soil analysis, appeared to agree with low resistivity zones in EM result. Therefore, small loop EM method can be applied to obtain rapidly the soil properties such as salt accumulation in a rice field. If research on soil property and EM responses of unsaturated zone would be conducted consistently, small loop EM method can be used effectively to detect salt accumulated zone in agricultural area.

Higher-Order Conditional Random Field established with CNNs for Video Object Segmentation

  • Hao, Chuanyan;Wang, Yuqi;Jiang, Bo;Liu, Sijiang;Yang, Zhi-Xin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.9
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    • pp.3204-3220
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    • 2021
  • We perform the task of video object segmentation by incorporating a conditional random field (CRF) and convolutional neural networks (CNNs). Most methods employ a CRF to refine a coarse output from fully convolutional networks. Others treat the inference process of the CRF as a recurrent neural network and then combine CNNs and the CRF into an end-to-end model for video object segmentation. In contrast to these methods, we propose a novel higher-order CRF model to solve the problem of video object segmentation. Specifically, we use CNNs to establish a higher-order dependence among pixels, and this dependence can provide critical global information for a segmentation model to enhance the global consistency of segmentation. In general, the optimization of the higher-order energy is extremely difficult. To make the problem tractable, we decompose the higher-order energy into two parts by utilizing auxiliary variables and then solve it by using an iterative process. We conduct quantitative and qualitative analyses on multiple datasets, and the proposed method achieves competitive results.

A Study on the Development of Road Traffic Safety Moderator Robot using AHP (AHP분석을 통한 도로 교통안전지킴이 로봇 개발에 관한 연구)

  • Lee, Young Woo;Kwon, Hyuck Jun
    • International Journal of Highway Engineering
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    • v.16 no.6
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    • pp.159-167
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    • 2014
  • PURPOSES : The purpose of this study is to analyze the requirements of the road traffic safety moderator robot when road repairing. The road traffic safety moderator robot is road traffic safety equipment and to conversions mechanical engineering and IT when road repairing. METHODS : The study used AHP based on the survey from road repair related expert that field engineers, design engineers, public officials and professors. The survey used paired comparison. The survey items were safety, convenience and economics. The safety is classified as visibility or efficiency, the convenience is classified as utility or mobility and the economics is classified as initial investment cost or maintenance $ management cost. The survey alternatives were the road traffic safety moderator robot, traffic regulation by human, traffic regulation by mannequin and traffic signs. The software for AHP is Expert Choice 2000. RESULTS : The results of AHP analyze, the weighted value of safety was analyzed with the highest at 0.488 of survey items. The weighted value of convenience was analyzed at 0.295, the weighted value of economics was analyzed at 0.218. The results of the road traffic safety moderator robot, the weight value of efficiency and utility were analyzed with the highest at 0.284 and 0.259 of alternatives. The weighted value of initial investment cost and maintenance & management cost were analyzed with the lowest at 0.203 and 0.211 of alternatives. The consistency test results of each items, null hypothesis is rejected because the CR values were 0.000 respectively. Therefore, the study results are consistency. CONCLUSIONS : The result of this study, overall value of the road traffic safety moderator robot came off second-best of other alternatives. The road traffic safety moderator robot has been received highest praise by the result of the study as good road traffic safety equipment when road repairing because the weighted values of efficiency and utility were analyzed with the highest of survey items. The efficiency mean securing safety and the utility mean practical assistance when road repairing. The results of this study showed that the road traffic safety moderator robot will effective for traffic safety when road repairing. economics and visibility are that supplementation of the road traffic safety moderator robot because the weighted values of economics and visibility were analyzed with the lowest of survey items. The consistency test results are consistency because the CR values were 0.000 respectively.

Congruity effects of University Students' Self-Image on the Satisfaction to Social Enterprise: Focused on SEN Clubs (사회적기업에 대한 대학생의 자아이미지 일치성이 고객만족에 미치는 영향: SEN 동아리를 중심으로)

  • Lee, II-Han
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.5
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    • pp.175-185
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    • 2019
  • Despite the rapid growth and importance of social enterprises in recent years, most social enterprises have many limitations such as small business size, financial dependence on government, lack of professional management personnel and knowledge, and low consumer awareness. Therefore, empirical research in the field of marketing is needed for economic independence of social enterprises. This study is based on the following: First, the identity of the social enterprise and the self-image of the consumer, second, the functional correspondence between the consumer's expectation and actual performance of the social enterprise's product, and third, the social value of the social enterprise product, the purpose of this study was to examine the effects of consumer value consistency on customer satisfaction and loyalty to social enterprises. Finally, this study aimed to suggest the moderating role of social enterprise clubs in this process to give implications for the long-term marketing of social enterprises. The results of this study are as follows. First, self-image consistency, functional correspondence, and value correspondence all have positive effects on the satisfaction of social enterprise and its products and form a loyalty. Secondly, whether or not the social enterprise club belonged to them is a moderating variable that raises sensitivity in the effects of self image consistency and functional consistency on customer satisfaction and customer satisfaction on loyalty. It was found to be.

Study on the Improvement of the Radiation Work Field Classification System in Republic of Korea (국내 방사선종사자 피폭 분류체계 개선에 관한 연구)

  • Su-Hui Park;Ji-Young Han;Yong-Min Kim
    • Journal of the Korean Society of Radiology
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    • v.17 no.2
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    • pp.267-275
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    • 2023
  • Occupational exposure records are subject of global interest, and analysis of radiation workers in work categories is being conducted. In Rep. of Korea, according to relevant ministries, the MOHW(Ministry of Health and Welfare), the MAFRA(Ministry of Agriculture, Food and Rural Affairs), and the NSSC(Nuclear Safety and Security Commission) collect and analyze records of occupational exposure by dividing them into 11 work categories. However, this classification system lacks consistency with the systems of major countries, including the UNSCEAR(United Nations Scientific Committee on the Effects of Atomic Radiation). The domestic radiation work field classification system does not have clear classification criteria and does not reflect the characteristics of the radiation work field. Through the analysis of the classification system of the UNSCEAR, we suggested the five main categories(nuclear cycle, medical, industrial, others(education/research, military/public) field and several sub-categories according to each radiation work field.

Relationship between Occupational Electromagnetic Field Exposure and Leukemia : A Meta-Analysis (직업성 전자장 노출과 백혈병 발생에 관한 메타분석)

  • Kim, Yoon-Shin;Song, Hae-Hiang;Hong, Seung-Cheol;Cho, Yong-Sung
    • Journal of Preventive Medicine and Public Health
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    • v.33 no.1
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    • pp.125-133
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    • 2000
  • Objectives : This study uses meta-analysis methodology to examine the statistical consistency and importance of random variation among results of epidemiologic studies of occupational electromagnetic field exposure and leukemia. Methods : Studies for this meta-analysis were identified from previous reviews and by asking researcher active in this field for recommendations. Overall, 27 studies of occupational electromagnetic field exposures and leukemia were reviewed. A variety of meta-analysis statistical methods have been used to assess combined effects, to identify heterogeneity, and to provide a single summary risk estimate based on a set of simiar epidemiologic studies. In this study, classification of exposure metircs on occupational epidemiologic studies are reported for (1) job classification (20 individual studies); (2) leukemia subtypes (13 individual studies); and (3) country (27 individual studies). Results : Results of this study, an inverse-variance weighted pooling of all the data leads to a small but significant elevation in risk of f 1% (OR=1.11, 95% CI : $1.06\sim1.16$) among 27 occupational epidemiologic studies. Publication bias was assessed by the 'fail-safe n' that may be not influence for all combined results exception a few categories, ie, 'power station operators' and 'electric utility workers' by job classification on occupational study. And ail combined odds ratio results were similar for fixed-effects models and random-effects models, with slightly higher risk estimates for the random-effects model in situations where there was significant heterogeneity, ie, Q-statistic significant (p<.05). Conclusions : We found a small elevation in risk of leukemia, but the ubiquitous nature of exposure to electromagnetic fields from workplace makes even a weak association a public health issue of substantial power to influence the present overall conclusion about relationship between electromagnetic fields exposure and leukemia.

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