• Title/Summary/Keyword: reliability sensitivity

Search Result 730, Processing Time 0.026 seconds

Convergence of the Image Evaluation by BI-RADS Classification in Accordance with Algorithms in DR Mammography (디지털 유방촬영술에서 BI-RADS의 구분에 따른 알고리즘별 영상의 융복합적 평가)

  • Lee, Mi-Hwa
    • Journal of Digital Convergence
    • /
    • v.13 no.9
    • /
    • pp.489-495
    • /
    • 2015
  • Image availability evaluated by the degree of agreement and sensitive using the process improve visualization according to the Algorithm modification in Image Post-Processing. Reliability measured by the Breast Imaging Reporting and Data System. 172 patients visit same period divided by BI-RADS, category five stages, and contents of breast parenchyma into Calcification, Nodule and Mass. Evaluated the TE/PV image reliability, visualization sensitive, agreement of diagnosis. Convergence analysis was an in various fields. According to the result of this research, PV has higher sensitive and accuracy about lesions than TE visual and there is a difference insensitive by contents of breast parenchyma. Therefore, practical use of Algorithm Modification(Tissue Equalization: TE, Premium View: PV) is expected to improve more accurate, useful diagnosis, which has not been easy until now.

Key Parameter of Peel-off Test for Reliability Assessment of Toner Film (토너 박막의 신뢰성 평가를 위한 Peel-off Test의 주요인자)

  • Kim, Kwang-Il;Kim, Dae-Eun
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.34 no.11
    • /
    • pp.1567-1573
    • /
    • 2010
  • In printing systems, the reliability of printed material depends on the ability of the toner film to remain adhered to the paper surface. In order to measure the strength between the toner film and the paper surface, a peel-off test is often performed. After conducting the test, the amount of toner film remaining on the paper is measured in order to determine the interfacial strength. The results of this test can be affected by many factors such as the peeling rate, weight of the roller used, and dwell time of tape. Sensitivity analysis was performed with respect to peeling rate, weight of roller and dwell time of tape at different levels. It was found that the interfacial strength increased with an increase in these main parameters. On the other hand, the trend with respect to the percentage of toner loss was different. Further, the interfacial strength and percentage of toner loss were significantly affected by the peeling rate.

A Study on the Analysis of Efficiency for Underground Distribution Equipment by Installment Ways (지중배전공사에 설치되는 기기의 설치위치에 따른 영향 분석에 관한 연구)

  • Kim, Joon-Eel;Kim, Dong-Myung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.23 no.12
    • /
    • pp.83-89
    • /
    • 2009
  • The environment of electrical power industry is now faced on problems such as electric rates, an increasing sensitivity in society with environmental issues and energy factors. Up to now, reliability is greatly influenced by maintenance and environmental factors that are unique to the electric utilities. The reliability is a characteristic assigned to the electric power systems's function which is related to the concept of installment of equipment. Therefore this reports's key finding is that it is important that the utilities track their individual components' value over investment expense of their installed components. This can be accomplished to consider the cases of foreign electric power companies and take into account the various possible installment ways of equipment in Korea. These results are expected to be used as a reference material for design underground distribution facilities and future applications.

Probabilistic Analysis and Design of the Spacing of Prefabricated Vertical Drains Considering Uncertainties in Geotechnical Property (지반 불확실성을 고려한 연직배수재 배치간격의 확률론적 해석과 결정)

  • Kim, Bang-Sig;Kim, Byung-Il
    • Journal of the Korean Geotechnical Society
    • /
    • v.23 no.4
    • /
    • pp.125-132
    • /
    • 2007
  • The oedometer, radial CRS and Rowe cell tests, composite discharge capacity tests and smear effect tests are carried out to estimate the parameters for the reliability-based design of vertical drain method. Also the sensitivity analysis, the probabilistic and deterministic solutions of radial consolidation theory are presented. The result of probabilistic analysis was compared to that of deterministic analysis using the tested and estimated parameters. The results indicated that the drain spacing in the deterministic method is larger than that in the probabilistic method because the former does not consider the uncertainties in the geotechnical property. The divergence of two methods is dependent on the probability of achieving target degree of consolidation by a given time and the coefficient of variation (COV) of the coefficient of horizontal consolidation ($c_h$).

Metaheuristic models for the prediction of bearing capacity of pile foundation

  • Kumar, Manish;Biswas, Rahul;Kumar, Divesh Ranjan;T., Pradeep;Samui, Pijush
    • Geomechanics and Engineering
    • /
    • v.31 no.2
    • /
    • pp.129-147
    • /
    • 2022
  • The properties of soil are naturally highly variable and thus, to ensure proper safety and reliability, we need to test a large number of samples across the length and depth. In pile foundations, conducting field tests are highly expensive and the traditional empirical relations too have been proven to be poor in performance. The study proposes a state-of-art Particle Swarm Optimization (PSO) hybridized Artificial Neural Network (ANN), Extreme Learning Machine (ELM) and Adaptive Neuro Fuzzy Inference System (ANFIS); and comparative analysis of metaheuristic models (ANN-PSO, ELM-PSO, ANFIS-PSO) for prediction of bearing capacity of pile foundation trained and tested on dataset of nearly 300 dynamic pile tests from the literature. A novel ensemble model of three hybrid models is constructed to combine and enhance the predictions of the individual models effectively. The authenticity of the dataset is confirmed using descriptive statistics, correlation matrix and sensitivity analysis. Ram weight and diameter of pile are found to be most influential input parameter. The comparative analysis reveals that ANFIS-PSO is the best performing model in testing phase (R2 = 0.85, RMSE = 0.01) while ELM-PSO performs best in training phase (R2 = 0.88, RMSE = 0.08); while the ensemble provided overall best performance based on the rank score. The performance of ANN-PSO is least satisfactory compared to the other two models. The findings were confirmed using Taylor diagram, error matrix and uncertainty analysis. Based on the results ELM-PSO and ANFIS-PSO is proposed to be used for the prediction of bearing capacity of piles and ensemble learning method of joining the outputs of individual models should be encouraged. The study possesses the potential to assist geotechnical engineers in the design phase of civil engineering projects.

Research on RAM-C-based Cost Estimation Methods for the Supply of Military Depot Maintenance PBL Project (군직 창정비 수리부속 보급 PBL 사업을 위한 RAM-C 기반 비용 예측 방안 연구)

  • Junho Park;Chie Hoon Song
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.26 no.5
    • /
    • pp.855-866
    • /
    • 2023
  • With the rapid advancement and sophistication of defense weapon systems, the government, military, and the defense industry have conducted various innovative attempts to improve the efficiency of post-logistics support(PLS). The Ministry of Defense has mandated RAM-C(Reliability, Availability, and Maintainability-Cost) analysis as a requirement according to revised Total Life Cycle System Management Code of Practice in May 2022. Especially, for the project budget forecast of new PBL(Performance Based Logistics) business contacts, RAM-C is recognized as an obligatory factor. However, relevant entities have not officially provided guidelines or manuals for RAM-C analysis, and each defense contractor conducts RAM-C analysis with different standards and methods to win PBL-related business contract. Hence, this study aims to contribute to the generalization of the analysis procedure by presenting a cost analysis case based on RAM-C for the supply of military depot maintenance PBL project. This study presents formulas and procedures to determine requirements of military depot maintenance PBL project for repair parts supply. Moreover, a sensitivity analysis was conducted to find the optimal cost/utilization ratio. During the process, a correlation was found between supply delay and total cost of ownership as well as between cost variability and utilization rate. The analysis results are expected to provide an important basis for the conceptualization of the cost analysis for the supply of military depot maintenance PBL project and are capable of proposing the optimal utilization rate in relation to cost.

Development of a simplified malnutrition screening tool for hospitalized patients and evaluation of its inter-methods reliability (입원환자의 초기영양평가를 위한 단순영양검색도구 개발 및 도구 간 신뢰도 검증)

  • Yun, Oak Hee;Lee, Gyuhwi;Park, Yoon Jung
    • Journal of Nutrition and Health
    • /
    • v.47 no.2
    • /
    • pp.124-133
    • /
    • 2014
  • Purpose: The current study was designed for development of a simplified malnutrition screening tool (SMST) for hospitalized patients using readily available laboratory and patient information and for evaluation of its reliability compared to well-established tools, such as PGSGA and NRS-2002. Methods: Anthropometric and biochemical measurements, as well as a few subjective assessments, of 903 patients who were preclassified by their nutritional status according to PGSGA were analyzed. Among them, a combination of factors, including age, BMI, albumin, cholesterol, total protein, hematocrit, and changes in body weight and food intake, were statistically selected as variables for SMST. Results: According to SMST, 620 patients (68.7%) were classified as the normal group and 283 patients (31.3%) were classified as the malnutrition group. Significant differences in age, albumin, TLC, BMI, hemoglobin, hematocrit, total protein, cholesterol, and length of stay were observed between the two groups. For inter-methods reliability, the screening results by SMST were compared with those by PGSGA and NRS-2002. The comparison with PGSGA and NRS-2002 showed 'Substantial agreement' (sensitivity 94.4%, specificity 88.4%, ${\kappa}$ = 0.747) and 'Moderate agreement' (sensitivity 96.1%, specificity 79.5%, ${\kappa}$ = 0.505), respectively, indicating that SMST held high inter-methods reliability. Conclusion: In conclusion, SMST, based on readily available laboratory and patient information and simple subjective assessments on changes in food intake and body weight, may be a useful alternative tool with a simple but reliable risk index, especially in resource-limited domestic hospitals.

Development of Web Credibility Evaluation Model Using AHP (AHP를 이용한 웹 사이트 신뢰성 평가 모델 개발)

  • Kim, Young-Kee
    • Journal of Korean Library and Information Science Society
    • /
    • v.39 no.4
    • /
    • pp.51-69
    • /
    • 2008
  • This study tired to develop the web credibility evaluation model by calculating weighted values and sensitivities of indicators which presented on preceding researches using Analytic Hierarchy Process. "Expert Choice 2000" was used as the tool for analysing AHP. 25 experts are answered for this questionnaire who are selected by judgement sampling method, one of the non-probability sampling method. Also, sensitivity analyses was performed to graphically see how the alternatives change with respect to the importance of the indicators or sub-indicators. The main results are summarized as followings; i) importance analysis in first level factors: trust-worthiness(0,606), expertness(0.222), safety(0.173), ii) importance analysis in second level factors: trustfulness (0.519), reputation(0.087), usefulness (0.102), timeliness(0,093), competency(0.027), security(0.115), reliability(0,058). iii) some of the importance analysis in third level factors: the site provides comprehensive information that is attributed to a specific source(0.252), the site has articles that list citations and references(0.153), the site contains user opinions and reviews(0.072), etc. iv) sensitivity analyses showed that the importance of the indicators or sub-indicators are slightly changed with respect to the alternatives change.

  • PDF

Analysis for Willingness to Pay of the Advanced Railway System (차세대전동차 시스템 도입에 따른 이용자 지불의사금액 결정요인분석)

  • Ha, Oh-Keun;Kim, Yong-Jin;Oh, Mi-Young;Park, Dong-Joo;Lee, Soo-Beom
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.9 no.4
    • /
    • pp.113-122
    • /
    • 2010
  • Research and development related to advanced railway systems is currently underway presently to promote the maintenance and economic feasibility of subways, and the aim of such research and development is to enhance the functionality, passenger convenience, system safety and reliability assurance of the subway. In this situation, a study that predicts the effect that the development of such an advanced railway system would have on subway users is required. To this end, this study derived willingness to pay and decision factors with the introduction of an advanced railway system after surveying passengers who use subway lines 1~8. The Price Sensitivity Method (PSM) was applied to derive the willingness to pay in relation to user convenience (operating speed, ride comfort, safety, comfort, security and informativeness) with the introduction of an advanced railway system. In addition, willingness to pay and decision factors were examined after explaining the effects of introducing an advanced railway system in detail to subway users. Through the analysis, it was found that willingness to pay amounted to a premium of 148 won ~ 161 won with the introduction of an advanced railway system, and that this was affected by factors such as gender, frequency of use, satisfaction with comfort, and satisfaction with security.

Study on Standardization of Korean Version of Psychiatric Diagnostic Screening Questionnaire(K-PDSQ) (한국판 정신장애 진단 선별 질문지의 표준화 연구)

  • Choi, Hyeong-Keun;Jung, Sung-Won;Jo, Hyun-Ju;Kim, Jeong-Bum;Jung, Chul-Ho
    • Anxiety and mood
    • /
    • v.9 no.1
    • /
    • pp.31-37
    • /
    • 2013
  • Objective : The PDSQ is a brief and psychometrically strong self-report scale designed to screen for common DSM-IV Axis I disorders in clinical settings. In this study, the K-PDSQ was compared with the M.I.N.I.-Plus (Mini-International Neuropsychiatric Interview-Plus) for diagnostic validity and availability of the K-PDSQ as a part of standardization of the K-PDSQ. Methods : The 640 patients were evaluated with the K-PDSQ and the M.I.N.I.-Plus. Diagnosing with the M.I.N.I.-Plus, the diagnostic correspondence, administering time, sensitivity, specificity, ROC curve, and AUC of the K-PDSQ were evaluated. Results : For the diagnostic correspondence of the K-PDSQ, Cohen's kappa coefficient was .66 between the K-PDSQ and the M.I.N.I.-Plus. The administering time of the K-PDSQ was $18.2{\pm}11.80$ minutes. Both sensitivity and specificity of the K-PDSQ were higher: the mean sensitivity across 10 subscales of K-PDSQ was 86%; the mean specificity was 84%. All AUCs of each subscale were above .80, which were statistically significant. Conclusion : The K-PDSQ is valid and available as a diagnostic screening tool. It will be widely used in clinical settings for screening DSM-IV Axis I diagnosis because of its simplicity and high reliability.