• 제목/요약/키워드: sensitivity analysis

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Lack of Association between the hOGG1 Ser326Cys Polymorphism and Gastric Cancer Risk: a Meta-analysis

  • Li, Bai-Rong;Zhou, Guo-Wu;Bian, Qi;Song, Bin
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권4호
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    • pp.1145-1149
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    • 2012
  • Aim: To clarify any association between the hOGG1 Ser326Cys polymorphism and susceptibility to gastric cancer. Methods: A meta-analysis based on 11 eligible case-control studies involving 5,107 subjects was carried out to summarize the data on the association between hOGG1 Ser326Cys polymorphism and gastric cancer risk. Results: No association was found between hOGG1 Ser326Cys polymorphism and gastric cancer risk (dominant model: OR = 0.95, 95% CI: 0.83-1.09, p = 0.486, ph (p values for heterogeneity) = 0.419; additive model: OR = 1.02, 95% CI: 0.81-1.30, p = 0.850, ph = 0.181; recessive model: OR = 1.09, 95% CI: 0.80-1.48, p = 0.586, ph = 0.053). Subgroup analysis based on ethnicity (Asian and Caucasian) and smoking status (ever smoker and never smoker) did did notpresent any significant association. Sensitivity analysis did not perturb the results. Conclusions: This study strongly suggested there might be no association between the hOGG1 Ser326Cys polymorphism and gastric cancer risk. However, larger scale studies are needed for confirmation.

APPLICATION OF UNCERTAINTY ANALYSIS TO MAAP4 ANALYSES FOR LEVEL 2 PRA PARAMETER IMPORTANCE DETERMINATION

  • Roberts, Kevin;Sanders, Robert
    • Nuclear Engineering and Technology
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    • 제45권6호
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    • pp.767-790
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    • 2013
  • MAAP4 is a computer code that can simulate the response of a light water reactor power plant during severe accident sequences, including actions taken as part of accident management. The code quantitatively predicts the evolution of a severe accident starting from full power conditions given a set of system faults and initiating events through events such as core melt, reactor vessel failure, and containment failure. Furthermore, models are included in the code to represent the actions that could mitigate the accident by in-vessel cooling, external cooling of the reactor pressure vessel, or cooling the debris in containment. A key element tied to using a code like MAAP4 is an uncertainty analysis. The purpose of this paper is to present a MAAP4 based analysis to examine the sensitivity of a key parameter, in this case hydrogen production, to a set of model parameters that are related to a Level 2 PRA analysis. The Level 2 analysis examines those sequences that result in core melting and subsequent reactor pressure vessel failure and its impact on the containment. This paper identifies individual contributors and MAAP4 model parameters that statistically influence hydrogen production. Hydrogen generation was chosen because of its direct relationship to oxidation. With greater oxidation, more heat is added to the core region and relocation (core slump) should occur faster. This, in theory, would lead to shorter failure times and subsequent "hotter" debris pool on the containment floor.

신뢰성 해석을 이용한 심해용 내압용기의 설계 최적화 (Design Optimization of a Deep-sea Pressure Vessel by Reliability Analysis)

  • 정태환;노인식;이재환;한승호
    • 한국해양공학회지
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    • 제19권2호
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    • pp.40-46
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    • 2005
  • In order to consider the statistical properties of probability variables which are used in structural analysis, the conventional approach of using safety factors based on past experience, are usually used to estimate the safety of a structure. The real structures could only be analyzed with the error in estimation of loads, materials and dimensional characteristics. Errors should be considered systematically in the structural analysis. In this paper, we estimated the probability of failure of two pressure vessels, simultaneously, using computational analysis. One pressure vessel, theoretically, had no stiffener whereas the other had. This paper also discusses sensitivity values of random variables in the rounded parts of the pressure vessel which had ring-style stiffener in the center of the external area which had ring-style stiffener. Finally, we show that the reliability index, and the probability of failure, can be calculated to particular tolerance limits.

문화간호역량 개념 분석 (A Concept Analysis of Cultural Nursing Competence)

  • 정금희;박혜숙;김경원;김영희;이선희;김현경
    • 여성건강간호학회지
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    • 제22권2호
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    • pp.86-95
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    • 2016
  • Purpose: The aim of this study was to conduct a concept analysis of cultural nursing competence. Methods: Cultural nursing competence was analyzed using Rodgers' evolutionary concept development method. A literature search using the keywords "cultural nursing competence", "intercultural nursing competence", "cultural nursing", "cultural health nursing", and "cultural competence" was conducted in PubMed, CINAHL, ERIC, and RISS on material published before 2015. Database and bibliographic searches yielded 35 records. Results: Cultural nursing competence comprised cognitive, affective, and behavioral domains. The critical attributes of the concept were sensitivity, equality, and activity. The analysis identified the following dimensions: awareness, openness, and coherence. The consequences of cultural nursing competence were personal satisfaction and social justice. The definition contained competence on both an individual and social level. Conclusion: Cultural competency enhances quality of care by narrowing health disparities and increasing client satisfaction. The concept analysis of cultural nursing competence may offer an acceptable framework which can be used to develop psychometric tools of this concept and provide guidelines in nursing practice.

Pro Variant of TP53 Arg72Pro Contributes to Gastric Cancer Risk in Asians: Evidence from a Meta-analysis

  • Su, Xiu-Li;Jin, Jian-Jun
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권3호
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    • pp.915-921
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    • 2012
  • Background: Previous studies investigating the association between TP53 Arg72Pro polymorphism and gastric cancer (GC) risk in Asian population have reported controversial results. Thus, a meta-analysis was performed. Methods: A comprehensive literature search was conducted and 17 case-control studies were finally included, involving a total of 5,990 GC cases and 6,812 controls. Subgroup analyses were performed by the sample size. Results: Meta-analysis of all 17 studies showed variant genotypes of TP53 Arg72Pro to be associated with an elevated GC risk in three genetic comparison models ($OR_{Pro\;vs.\;Arg}$=1.13, 95%CI 1.03-1.25, $P_{OR}$=0.01; $OR_{Homozygote\;comparison\;model}$=1.33, 95%CI 1.07-1.64, $P_{OR}$=0.009; $OR_{Dominant\;genetic\;model}$=1.13, 95%CI 1.05-1.22, $P_{OR}$=0.002). Besides, a more obvious association was observed after the heterogeneity was decreased (all P values less than 0.001). This association was further identified by both subgroup and sensitivity analyses. Conclusions: This meta-analysis suggests the Pro variant of TP53 Arg72Pro contributes to gastric cancer risk in Asians.

Dynamic Analysis of Francis Runners - Experiment and Numerical Simulation

  • Lais, Stefan;Liang, Quanwei;Henggeler, Urs;Weiss, Thomas;Escaler, Xavier;Egusquiza, Eduard
    • International Journal of Fluid Machinery and Systems
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    • 제2권4호
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    • pp.303-314
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    • 2009
  • The present paper shows the results of numerical and experimental modal analyses of Francis runners, which were executed in air and in still water. In its first part this paper is focused on the numerical prediction of the model parameters by means of FEM and the validation of the FEM method. Influences of different geometries on modal parameters and frequency reduction ratio (FRR), which is the ratio of the natural frequencies in water and the corresponding natural frequencies in air, are investigated for two different runners, one prototype and one model runner. The results of the analyses indicate very good agreement between experiment and simulation. Particularly the frequency reduction ratios derived from simulation are found to agree very well with the values derived from experiment. In order to identify sensitivity of the structural properties several parameters such as material properties, different model scale and different hub geometries are numerically investigated. In its second part, a harmonic response analysis is shown for a Francis runner by applying the time dependent pressure distribution resulting from an unsteady CFD simulation to the mechanical structure. Thus, the data gained by modern CFD simulation are being fully utilized for the structural design based on life time analysis. With this new approach a more precise prediction of turbine loading and its effect on turbine life cycle is possible allowing better turbine designs to be developed.

PROCESS OF DESIGNING BODY STRUCTURES FOR THE REDUCTION OF REAR SEAT NOISE IN PASSENGER CAR

  • Kim, K.C.;Kim, C.M.
    • International Journal of Automotive Technology
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    • 제8권1호
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    • pp.67-73
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    • 2007
  • This study analyzes the interior noise that is generated during acceleration of a passenger car in terms of car body structure and panel contribution. According to the transfer method, interior noise is classified into structure-borne noise and air-borne noise. Structure-borne noise is generated when the engine's vibration energy, an excitation source, is transferred to the car body through the engine mount and the driving system and the panel of the car body vibrates. When structure-borne noise resonates in the acoustic cavity of the car interior, acute booming noise is generated. This study describes plans for improving the car body structure and the panel form through a cause analysis of frequency ranges where the sound pressure level of the rear seat relative to the front seat is high. To this end, an analysis of the correlation between body attachment stiffness and acoustic sensitivity as well as a panel sensitive component analysis were conducted through a structural sound field coupled analysis. Through this study, via research on improving the car body structure in terms of reducing rear seat noise, stable performance improvement and light weight design before the proto-car stage can be realized. Reduction of the development period and test car stage is also anticipated.

제동 장치 최적 설계 모듈 개발 (Development of the Optimization Design Module of a Brake System)

  • 정성필;박태원
    • 한국자동차공학회논문집
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    • 제16권3호
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    • pp.166-171
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    • 2008
  • In this paper, the optimization design module for the brake system of a vehicle is developed. As using this module, design variables, that minimize an object function and satisfy nonlinear constraint conditions, can be found easily. Before an optimization is operated, Plackett-Burman design, one of the factorial design methods, is used to choose the design variables which affect a response function significantly. Using the response surface analysis, second order recursive model function, which informs a relation between design variables and response function, is estimated. In order to verify the reliability of the model function, analysis of variances(ANOVA) table is used. The value of design variables which minimize the model function and satisfy the constraint conditions is predicted through Sequential Quadratic-Programming (SQP) method. As applying the above procedure to a real vehicle simulation model and comparing the values of object functions of a current and optimized system, the optimization results are verified.

대기중 미량금속의 발암 위해도에 대한 몬테 카를로 분석 (Monte Calro Analysis of Cancer Risk from Airborne Trace Metals)

  • 장미숙;이진홍
    • 한국대기환경학회지
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    • 제18권6호
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    • pp.465-474
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    • 2002
  • In order to reflect variability due to exposure factors as well as to assess uncertainty associated with cancer risk posed by airborne trace metals, a Monte Calro analysis has been made in this study. Input parameters for Monte Carlo analysis were developed or adjusted using body weight, lifetime, and exposure frequency of Koreans. Ambient distributions of toxic metals were founded to be lognormal distributions for most of them using goodness-of-fit tests. Thus, the 95% UCL and 95% LCL of carcinogenic metals were estimated by H-statistic method for lognormal distribution, respectively. The results of Monte Carlo analysis of 95% UCL showed that the 95th percentile risks for men and women were 1.2 and 1.1 times higher than an acceptable risk of 10$^{-5}$ , respectively. The probabilities which those risks exceed the acceptable risk were estimated to be 8% and 6%, respectively, while to be 95% and 94%, respectively on the basis of the minimum acceptable risk of 10$^{-6}$ , respectively. Approximately 90% of total cancer risk came from human carcinogens such as arsenic and hexavalent chromium. Therefore, it is necessary to properly manage both arsenic and hexavalent chromium emissions in the study area.

SWAT 모형을 이용한 대유역 강우-유출해석: 메콩강 유역을 중심으로 (Large Scale Rainfall-runoff Analysis Using SWAT Model: Case Study: Mekong River Basin)

  • 이대업;유완식;이기하
    • 한국농공학회논문집
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    • 제60권1호
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    • pp.47-57
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    • 2018
  • This study implemented the rainfall-runoff analysis of the Mekong River basin using the SWAT (Soil and Water Assessment Tool). The runoff analysis was simulated for 2000~2007, and 11 parameters were calibrated using the SUFI-2 (Sequential Uncertainty Fitting-version 2) algorithm of SWAT-CUP (Calibration and Uncertainty Program). As a result of analyzing optimal parameters and sensitivity analysis for 6 cases, the parameter ALPHA_BF was found to be the most sensitive. The reproducibility of the rainfall-runoff results decreased with increasing number of stations used for parameter calibration. The rainfall-runoff simulation results of Case 6 showed that the RMSE of Nong Khai and Kratie stations were 0.97 and 0.9, respectively, and the runoff patterns were relatively accurately simulated. The runoff patterns of Mukdahan and Khong Chaim stations were underestimated during the flood season from 2004 to 2005 but it was acceptable in terms of the overall runoff pattern. These results suggest that the combination of SWAT and SWAT-CUP models is applicable to very large watersheds such as the Mekong for rainfall-runoff simulation, but further studies are needed to reduce the range of modeling uncertainty.