• Title/Summary/Keyword: aggregation index

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Pulsatility Index of Blood Echogenicity of the Human Radial and Common Carotid Arteries: Relation with Age and Stroke (인체 요골동맥과 경동맥의 혈액에코박동지수: 나이 및 뇌졸중과의 관계)

  • Bok, Tae-Hoon;Kong, Qi;Nam, Kweon-Ho;Choi, Jay Chol;Paeng, Dong-Guk
    • Journal of the Korean Society for Nondestructive Testing
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    • v.32 no.5
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    • pp.494-501
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    • 2012
  • In the present paper, the ultrasound blood images were measured at both the human radial artery(RA) and common carotid artery(CCA), depending on the age, and the pulsatility index of blood echogenicity(PIBE) was analyzed. In addition, the ultrasound blood images were measured at both RA and CCA of both the stroke patients and the control group, and PIBE was compared. PIBE of RA for the young group was similar with that for the old group ($0.13{\pm}0.11$ and $0.16{\pm}0.03$). PIBE of CCA for the young group, however, was larger than that for the old group ($0.70{\pm}0.21$ and $0.32{\pm}0.01$), and was more variable depending on the subject. Similarly, the fibrinogen concentrations of the patients ($336{\pm}61$ and $340{\pm}126mg/dl$) were more than that of the control group ($264{\pm}38$ and $257{\pm}43mg/dl$), for both RA and CCA. The results indicate the possibility of the ultrasonic test on the correlation between erythrocyte aggregation and stroke, and it is expected that the in-vivo EA measurement would be clinically useful.

Study on the Oil Resistance, Morphological and Dynamic Mechanical Properties, Flame Retardance of Ethylene Vinyl Acetate Copolymer and Ethylene Propylene Rubber Compounds

  • Sung, Il Kyung;Lee, Won Ki;Park, Chan Young
    • Elastomers and Composites
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    • v.52 no.1
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    • pp.27-34
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    • 2017
  • In this experiment, blends of ethylene vinyl acetate rubber (EVM) with a vinyl acetate (VA) content greater than 40 wt% and ethylene propylene rubber (EPM) were prepared by mechanical mixing; a number of parameters of the blends, including oil resistance, morphological and dynamic mechanical properties and flame retardancy, were subsequently measured. In the $100^{\circ}C$ oil resistance test, both the ammonium polyphosphate/dipentaerythritol/expandable graphite (APP/DPER/EG) and aluminum hydroxide (ATH) flame retardant systems showed an increase in volume change with increasing EPM content. For the ATH system, the dispersion shape was coarse and aggregation was observed. The results of a dynamic mechanical test showed slightly higher E' and E'' for the APP/DPER/EG flame retardant system when compared to the single ATH system. For both the APP/DPER/EG and ATH systems, the limited oxygen index (LOI) tests performed at increasing content of EPM showed a LOI value higher than 30, indicating excellent flame resistance.

Effect of Antiplatelets in Diabetic Peripheral Vasculopathy: Comparison by Ankle-Brachial Index and Peak Wave Velocity (당뇨병성 말초혈관병증에서 항혈소판제의 효과: 발목상완지수 및 맥파전달속도를 통한 비교)

  • Park, Se-Jin
    • Journal of Korean Foot and Ankle Society
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    • v.18 no.4
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    • pp.159-164
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    • 2014
  • Purpose: The purpose of this study is to confirm the effect of antiplatelet drugs in diabetic peripheral vasculopathy in diabetic foot patients. Materials and Methods: We designed a retrospective study in diabetic foot patients with diabetic peripheral vasculopathy. From October 2007 to December 2013, 278 cases in 139 patients who took antiplatelet drugs over at least a six-month period were included in this study. We categorized these patients according to the type of drug used. The efficacy of antiplatelet drugs was evaluated using anklebrachial index (ABI) and pulse wave velocity (PWV). Results: Only the aspirin group showed a statistically significant increase of ABI after antiplatelet therapy ($1.10{\pm}0.12$ to $1.12{\pm}0.11$). In addition, only the cilostazol group showed a statistically significant decrease of PWV after antiplatelet therapy ($1,701.20{\pm}396.56$ to $1,627.42{\pm}324.98$). Conclusion: Aspirin and cilostazol may be used in treatment of diabetic peripheral vasculopathy, whereas dual antiplatelet therapy with aspirin and clopidogrel has no specific benefits in diabetic peripheral vasculopathy.

Credit Risk Evaluations of Online Retail Enterprises Using Support Vector Machines Ensemble: An Empirical Study from China

  • LI, Xin;XIA, Han
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.8
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    • pp.89-97
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    • 2022
  • The e-commerce market faces significant credit risks due to the complexity of the industry and information asymmetries. Therefore, credit risk has started to stymie the growth of e-commerce. However, there is no reliable system for evaluating the creditworthiness of e-commerce companies. Therefore, this paper constructs a credit risk evaluation index system that comprehensively considers the online and offline behavior of online retail enterprises, including 15 indicators that reflect online credit risk and 15 indicators that reflect offline credit risk. This paper establishes an integration method based on a fuzzy integral support vector machine, which takes the factor analysis results of the credit risk evaluation index system of online retail enterprises as the input and the credit risk evaluation results of online retail enterprises as the output. The classification results of each sub-classifier and the importance of each sub-classifier decision to the final decision have been taken into account in this method. Select the sample data of 1500 online retail loan customers from a bank to test the model. The empirical results demonstrate that the proposed method outperforms a single SVM and traditional SVMs aggregation technique via majority voting in terms of classification accuracy, which provides a basis for banks to establish a reliable evaluation system.

Estimating the Spatial Distribution of Satellite Image Classification Error Using Index of Spatial Distribution (공간분포지표를 이용한 위성영상 분류오차의 공간적 분포 평가)

  • 이병길;김용일;어양담
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.17 no.2
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    • pp.129-136
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    • 1999
  • The quality of image classification results is not always uniform over entire image. Thus, this study proposes the concept of ISDd (Index of Spatial Distribution by distance) and ISDs (ISD by scatteredness) for the evaluation of unevenness of result quality, and spatial distribution of satellite image classification errors. The ISDd is indexed mean distance of misclassified pixels and the ISDs is statistical indicator of scatteredness of misclassified pixels. In this study, the ISDd and the ISDs are calculated and evaluated for some satellite images, then misclassified area is extracted and the reasons of misclassification are examined. As the result of this study, using both the ISDd and the ISDs, the basis of decision on adoption/rejection of classification results is offered at sub-image level by evaluation of the local aggregation of misclassified pixels. Using Index of Spatial Distribution. as well as overall classification accuracy, users can understand the spatial distribution of misclassified pixels, and can have the additional criterion of the judgement on suitability and reliability of classification results.

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Performance Evaluation System Framework for Natural Disaster Research and Development Projects (자연재난분야 연구개발 사업의 특성을 고려한 성과지표 및 성과평가체계 개발)

  • Kim, Du-Yon;Kim, Sang-Bum;Kwak, Hyun-Jun
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.4
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    • pp.118-129
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    • 2013
  • Due to the recent surge in natural disasters, with rising social concerns, investment on research & development (R&D) project in natural disaster mitigation area is continuously increasing. However, current R&D performance management system of natural disaster mitigation area does not properly reflect characteristics and social ripple effects of R&D projects. It is indicated that mainly due to the current performance index consists of easy-quantification factors and the performance evaluation system adopts simple aggregation method. Therefore, the purpose of this study is to develop new performance evaluation system considering characteristics and social ripple effects of natural disaster mitigation R&D projects. To this ends, this study derived 3-dimensional performance measurement index through literature review and natural disaster mitigation R&D projects analysis. Finally, based on the derived performance measurement index, this study suggested new and effective performance evaluation system for natural disaster mitigation R&D projects.

A Study on the Development of National Composite S&T Indices and Their Application (국가종합과학기술지수의 도출과 적용: 종합지수를 통한 주요 선진국과의 국가과학기술활동 비교)

  • Mun, Hye-Seon;Lee, Jeong-Dong
    • Journal of Technology Innovation
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    • v.13 no.1
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    • pp.55-71
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    • 2005
  • We attempt to make three composite Science and Technology (S&T) indices for overall understanding of national S&T by aggregation of various S&T indicators using fuzzy set theory and then use these Indices to compare the S&T activities of Korea with those of five developed countries (France, Germany, Japan, the U.K., the U.S.). The overall results suggest that although the S&T indices of Korea still lag behind those of developed countries, they have grown rapidly and continuously and, as a result, the S&T gaps between Korea and developed countries have narrowed. However, the capability of Korea to transform its R&D input into final economic output has not yet matched that of developed countries.

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A Study on the Aggregation and Structuring of Technological Knowledge Indicators (기술지식지표의 통합 및 구조화에 대한 연구)

  • 박광만;신준석;박용태
    • Proceedings of the Technology Innovation Conference
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    • 2003.02a
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    • pp.27-40
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    • 2003
  • Though it has been recognized that the accumulation of technological knowledge has been the core competency to reinforce the competitiveness of individual firms and to raise the innovation capability of social and economic systems, only single or fragmentary variables, such as R&D expenditure, R&D stock, the number of researchers and the number of R&D employee have been adopted to measure the amount of technological knowledge. In this research, we use nine conventional technological knowledge measures under the conceptual structure of input-output framework to technological knowledge. Applying correlation and factor analysis, we examine the relationships among the nine proxy measures quantitatively and suggest the new approach for the calculation of technological knowledge index as a aggregated measure.

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A Study of Business Cycle Index Using Dynamic Factor Model (동태적 요인모형을 이용한 경기동행지수 개발에 관한 연구)

  • Na, In-Gang;Sonn, Yang-Hoon
    • Environmental and Resource Economics Review
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    • v.9 no.5
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    • pp.903-924
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    • 2000
  • This paper examines the alternative method to measure the state of overall economic activity. The macroeconomic variables, used for business cycle, take more than a month after a period for collection and aggregation. The electricity generation data is compiled in mechanical ways just after the period. Based on this fact, we develop the two stage estimation method for coincident economic indicators in order to detect the business cycle in an earlier period, using Stock-Watson's Dynamic Factor Model. Using monthly data from 1970 to 1999, it is found that the experimental coincidence economic indicators are well-fitted to data and also that the estimates of two stage estimation method have good explanatory power, equivalent to the experimental coincidence economic indicators. While the RMSE of coincidence economic indicators is found to be 1.27%, that of the experimental coincidence economic indicators is found to be 1.31% and that of the two stage estimation method is around 1.44%. If we take consideration into the fact that it measures the business cycle in one month earlier, we come to the conclusion that the two stage estimation is of great use.

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Influence of Scaling in Drone-based Remotely Sensed Information on Actual Evapotranspiration Estimation (드론 원격정보 격자크기가 실제증발산량 산정에 미치는 영향)

  • Lee, Khil-Ha
    • Journal of Environmental Science International
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    • v.27 no.2
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    • pp.135-141
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    • 2018
  • The specification of surface vegetation is essential for simulating actual evapotranspiration of water resources. The availability of land cover maps based on remotely collected data makes the specification of surface vegetation easier. The spatial resolution of hydrologic models rarely matches the spatial scales of the vegetation data needed, and remotely collected vegetation data often are upscaled up to conform to the hydrologic model scale. In this study, the effects of the grid scale of of surface vegetation on the results of actual evapotranspiration were examined. The results show that the coarser resolution causes larger error in relative terms and that a more realistic description of area-averaged vegetation nature and characteristics needs to be considered when calculating actual evapotranspiration.