• Title/Summary/Keyword: quantitative evaluation method

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Evaluation of Image Quality using Monte Carlo Simulation in Digital Mammography System (디지털유방영상시스템에서 몬테카를로 시뮬레이션을 이용한 영상평가)

  • Kim, Changsoo;Kang, Se-Sik;Kim, Jung-Hoon;Lee, Jin-Soo
    • The Journal of the Korea Contents Association
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    • v.14 no.6
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    • pp.247-254
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    • 2014
  • For the purpose of early diagnosis of the breast cancer, the attention on the screening mammography has been increasing-with supply of digital mammography day by day. Image quality is decided by target materials and filter combinations. Optimized selection by a glandular density and a thickness is needed, because these combinations change x-ray spectrum and effect to image quality. The purpose of this study is to find out optimized target and filter combinations through the evaluation of quantitative image quality and to suggest means which minimize patient dose through MCNPX. In results, spatial frequency resolution evaluation which is quantitative image quality evaluation method, MTF, NPS, DQE shows that we have to select Mo/Mo combinations or Mo/Rh combinations when compressed breast is thin. but in case of that when compressed breast is thick, we have to select Rh/Rh combinations or W /Rh combinations. In a comprehensive evaluation, W!Rh combinations which are not used in thin breasts in practice was superior to all image quality evaluation. This result is somewhat different-with clinical examination results. Secondary end point was organ dose evaluation, radiation dose of opposite breast was approximately 47 ~73% effectiveness when selecting standard breast. In conculsion, the most important point is that we have to select the optimal combinations-with considering dose evaluation and various thickness.

Creep Damage Evaluation of High-Temperature Pipeline Material for Fossil Power Plant by Frequency Spectrum Analysis Method (주파수분석법에 의한 발전소 고온배관재료의 크리프손상 평가)

  • Lee, Sang-Guk;Lee, In-Cheol;Chang, Hong-Keun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.20 no.1
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    • pp.10-17
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    • 2000
  • In boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants, conventional measurement techniques(replica method, electric resistance method, and hardness test method) for measuring creep damage have such disadvantages as complex preparation and measurement procedures, too many control parameters. And also, these techniques have low practicality and applied only to component surfaces with good accessibility. It needs to apply a reliable and quantitative ultrasonic nondestructive evaluation method that can be replaced for these equipment. In this study, both artificial creep degradation test using life prediction formula and frequency analysis by ultrasonic tests for crept specimens were carried out for the purpose of nondestructive evaluation for creep damage. As a result of ultrasonic tests for crept specimens, we conformed that the high frequency side spectra decrease and central frequency components shift to low frequency band, and also their bandwidth decreases as increasing creep damage in backwall echos.

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Development and Evaluation of Image Segmentation Technique for Object-based Analysis of High Resolution Satellite Image (고해상도 위성영상의 객체기반 분석을 위한 영상 분할 기법 개발 및 평가)

  • Byun, Young-Gi;Kim, Yong-Il
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.6
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    • pp.627-636
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    • 2010
  • Image segmentation technique is becoming increasingly important in the field of remote sensing image analysis in areas such as object oriented image classification to extract object regions of interest within images. This paper presents a new method for image segmentation to consider spectral and spatial information of high resolution satellite image. Firstly, the initial seeds were automatically selected using local variation of multi-spectral edge information. After automatic selection of significant seeds, a segmentation was achieved by applying MSRG which determines the priority of region growing using information drawn from similarity between the extracted each seed and its neighboring points. In order to evaluate the performance of the proposed method, the results obtained using the proposed method were compared with the results obtained using conventional region growing and watershed method. The quantitative comparison was done using the unsupervised objective evaluation method and the object-based classification result. Experimental results demonstrated that the proposed method has good potential for application in the object-based analysis of high resolution satellite images.

Performance Evaluation of Repair Material and Method for Reinforced Concrete Structure by Long Term Exposure Experiment (장기폭로실험에 의한 철근콘크리트 구조물의 보수재료.공법 성능평가)

  • Kim, Moo-Han;Kim, Gyu-Yong;Cho, Bong-Suk;Kim, Young-Duck;Kim, Young-Sun
    • Journal of the Korea Concrete Institute
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    • v.19 no.1
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    • pp.39-46
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    • 2007
  • In this study, for the establishment of the performance evaluation methods and the quality control standards of durability recovery method, the quantitative exposure data by long term exposure test under the coast and normal atmosphere is accumulated and analyzed. Investigating and evaluating the result of exposure test during 30 months of exposure age under the coastal and normal atmosphere environment, carbonation depth and chloride-ion penetration depth very little penetrated than cover depth. It seems reasonable to conclude that main cause of Corrosion of reinforcing bar are chloride-ion and macro cell from the result of corrosion area and corrosion velocity. Therefore, it is considered to be applied as the fundamental data on the performance evaluation and quality control standards of repair material and method through continuous exposure test in the future.

Evaluation of a Drill Bit Button Arrangement for Enhanced Drilling Efficiency (천공 효율 향상을 위한 드릴비트 버튼배열 성능평가 방법)

  • Kang, Hoon;Cho, Jung Woo;Jeong, Myeong Sik;Cho, Yong Jae;Lee, Sang Kon;Lee, Jae Wook
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.6
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    • pp.575-581
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    • 2015
  • The drill bit, which directly transmits percussive forces and torque to the rock, is the core part of a rock drilling machine. For effective drilling, the button arrangement of a drill bit should be optimized because it is the most important design factor in determining drilling efficiency. Furthermore, a quantitative method is necessary to evaluate the button arrangement for the optimization of the drill bit button. Therefore, we propose a new method for the evaluation of the drill bit button arrangement using new evaluation indices, which include the overlapped impact area, blank area, and moment. Moreover, we verify the suitability of the proposed evaluation method by applying it to the conventional button arrangement.

How to improve the accuracy of recommendation systems: Combining ratings and review texts sentiment scores (평점과 리뷰 텍스트 감성분석을 결합한 추천시스템 향상 방안 연구)

  • Hyun, Jiyeon;Ryu, Sangyi;Lee, Sang-Yong Tom
    • Journal of Intelligence and Information Systems
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    • v.25 no.1
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    • pp.219-239
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    • 2019
  • As the importance of providing customized services to individuals becomes important, researches on personalized recommendation systems are constantly being carried out. Collaborative filtering is one of the most popular systems in academia and industry. However, there exists limitation in a sense that recommendations were mostly based on quantitative information such as users' ratings, which made the accuracy be lowered. To solve these problems, many studies have been actively attempted to improve the performance of the recommendation system by using other information besides the quantitative information. Good examples are the usages of the sentiment analysis on customer review text data. Nevertheless, the existing research has not directly combined the results of the sentiment analysis and quantitative rating scores in the recommendation system. Therefore, this study aims to reflect the sentiments shown in the reviews into the rating scores. In other words, we propose a new algorithm that can directly convert the user 's own review into the empirically quantitative information and reflect it directly to the recommendation system. To do this, we needed to quantify users' reviews, which were originally qualitative information. In this study, sentiment score was calculated through sentiment analysis technique of text mining. The data was targeted for movie review. Based on the data, a domain specific sentiment dictionary is constructed for the movie reviews. Regression analysis was used as a method to construct sentiment dictionary. Each positive / negative dictionary was constructed using Lasso regression, Ridge regression, and ElasticNet methods. Based on this constructed sentiment dictionary, the accuracy was verified through confusion matrix. The accuracy of the Lasso based dictionary was 70%, the accuracy of the Ridge based dictionary was 79%, and that of the ElasticNet (${\alpha}=0.3$) was 83%. Therefore, in this study, the sentiment score of the review is calculated based on the dictionary of the ElasticNet method. It was combined with a rating to create a new rating. In this paper, we show that the collaborative filtering that reflects sentiment scores of user review is superior to the traditional method that only considers the existing rating. In order to show that the proposed algorithm is based on memory-based user collaboration filtering, item-based collaborative filtering and model based matrix factorization SVD, and SVD ++. Based on the above algorithm, the mean absolute error (MAE) and the root mean square error (RMSE) are calculated to evaluate the recommendation system with a score that combines sentiment scores with a system that only considers scores. When the evaluation index was MAE, it was improved by 0.059 for UBCF, 0.0862 for IBCF, 0.1012 for SVD and 0.188 for SVD ++. When the evaluation index is RMSE, UBCF is 0.0431, IBCF is 0.0882, SVD is 0.1103, and SVD ++ is 0.1756. As a result, it can be seen that the prediction performance of the evaluation point reflecting the sentiment score proposed in this paper is superior to that of the conventional evaluation method. In other words, in this paper, it is confirmed that the collaborative filtering that reflects the sentiment score of the user review shows superior accuracy as compared with the conventional type of collaborative filtering that only considers the quantitative score. We then attempted paired t-test validation to ensure that the proposed model was a better approach and concluded that the proposed model is better. In this study, to overcome limitations of previous researches that judge user's sentiment only by quantitative rating score, the review was numerically calculated and a user's opinion was more refined and considered into the recommendation system to improve the accuracy. The findings of this study have managerial implications to recommendation system developers who need to consider both quantitative information and qualitative information it is expect. The way of constructing the combined system in this paper might be directly used by the developers.

A Study on the Method for Promoting Acceptance on Performance Management : Focusing on the Public Enterprises Practices (성과관리의 수용성 제고 방안 : 공기업사례를 중심으로)

  • Kim, Youn Sung;Yoo, Hong Sung;Kim, Sun Cheol
    • Journal of the Korean Operations Research and Management Science Society
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    • v.40 no.1
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    • pp.185-198
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    • 2015
  • This study drew performance management factors analyzed a causal link between acceptance and satisfaction of performance management to present the method for promoting acceptance on the performance management system that most of the public enterprises, government-affiliated organizations are implementing. To achieve this, qualitative analysis and quantitative analysis were conducted in parallel through in-depth case studies and surveys. The results of this study are as follows. First, the analysis of the performance management factors with preceding studies shows that performance management indicators, performance management operations and performance management communications. Second, from the causal relationship of performance management factors affecting performance management acceptance reveals that performance management operation has statistical significance. Third, the analysis of the effect of performance management factors on the management satisfaction shows that operation and indicator of the performance management have statistical significance and reflecting the performance indicators to business, adequacy of target level, training, system support and CEO's Leadership have been revealed as important variables to the management satisfaction. Fourth, the result of the analysis on casual connection between acceptance and satisfaction of the performance management shows that improving management acceptance has a direct impact on satisfaction because performance management receptiveness were deemed statistically significant. Fifth, the result of the in-depth case studies on improving performance management acceptance shows that public enterprises have been putting in an effort to design indicators and try to encourage internal member's involvement during the monitoring and evaluation. The quantitative analysis based on survey has turned out that performance management operation and performance management indicators have statistical significance. The qualitative analysis by in-depth analysis shows that public enterprises put a lot of effort to performance management indicators and communication between internal members. As a result, commitment to performance management operation is required to improve the performance management acceptance. In other words, a detailed implementation plan for training, information system support, and CEO's leadership has to be established and ought to be pushed.

Development of Impact Table and optimum combination dedication module for green-remodeling advance business value assessment

  • Choi, Jun-Woo;Kim, Gyoung-Rok;Ko, Jung-Lim;Shin, Jee-Woong;Lee, Keon-Ho
    • KIEAE Journal
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    • v.16 no.3
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    • pp.5-12
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    • 2016
  • Purpose: In case of existing building, A lot of attempts are being made like changing thermal system or using high efficiency products to decrease energy load and increase energy efficiency. However, (1) Absence of systemed database of green-remodeling technology and products. (2) Absence of comparative analysis system and qualitative/quantitative evaluation method of energy performance and energy reduction cost. (3) Existing remodeling was very hard to access for non-experts. So, in this paper, the authors developed data base for green-remodeling(Impact Table A, Impact Table B) and optimum combination dedication tool for user convenience. Accordingly, purpose of this paper validate usefulness of Impact Table and optimum alternative dedication tool. Method: For validate the usefulness of Impact Table and optimum combination dedication tool, the authors selected five test model office buildings. Next, through research investigation, the authors diagnosed the present state of buildings. In base of diagnosis results, select technologies for remodeling by qualitative comparison (Impact Table A). Next, evaluate quantitative price and performance technologies that selected in Impact Table A (Impact Table B). Lastly, through final evaluation of Impact Taba A and Impact Table B, determine the direction of the green-remodeling. Result: Impact Table and optimum combination dedication tool can use relative indicator for green-remodeling, especially through ROI by detail field.

A Study on the Evaluation Method of Defense Technology Valuation Using the Readability Level Assessment of Core National Defense Technology (국방 핵심기술의 성숙도(Readiness Level)평가를 활용한 국방기술가치평가 방안 연구)

  • Lee, Hyung-Seog;Shin, Chung-Jin;Kang, Seok-Joong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.23 no.12
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    • pp.1710-1719
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    • 2019
  • This study is intended to understand defense technologies that require the convergence of various technologies and the integration of systems, and to propose valuation methods that reflect the characteristics of each field. The measure of technology level, integration (system integration technology) between technologies, preparation of manufacturing, and maturity scale of the weapons system to be valued are measured according to the items of measurement factors to verify system performance, and to present a framework for estimating the quantitative values of core technologies using system maturity. Considering the characteristics of each technology field, the research suggests a proper valuation method. In evaluating the value of defense technologies, A proposal is made to evaluate the value of defense technology by competent technical experts in each field, using SRL, which can be evaluated according to the evaluation criteria reflecting the technical characteristics of each field, and to evaluate the completion of the entire system in quantitative terms.

Automated Attack Path Enumeration Method based on System Vulnerabilities Analysis (시스템 취약점 분석을 통한 침투 경로 예측 자동화 기법)

  • Kim, Ji Hong;Kim, Huy Kang
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.22 no.5
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    • pp.1079-1090
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    • 2012
  • As the number of information asset and their vulnerabilities are increasing, it becomes more difficult for network security administrators to assess security vulnerability of their system and network. There are several researches for vulnerability analysis based on quantitative approach. However, most of them are based on experts' subjective evaluation or they require a lot of manual input for deriving quantitative assessment results. In this paper, we propose HRMS(Hacking and Response Measurement System) for enumerating attack path using automated vulnerability measurement automatically. HRMS can estimate exploitability of systems or applications based on their known vulnerability assessment metric, and enumerate attack path even though system, network and application's information are not fully given for vulnerability assessment. With this proposed method, system administrators can do proactive security vulnerability assessment.