scholarly journals Multi-Index Evaluation for Flood Disaster from Sustainable Perspective: A Case Study of Xinjiang in China

2018 ◽  
Vol 15 (9) ◽  
pp. 1983 ◽  
Author(s):  
Yudan Dou ◽  
Xiaolong Xue ◽  
Zebin Zhao ◽  
Xiaowei Luo ◽  
Ankang Ji ◽  
...  
Keyword(s):  
Subjective Experience ◽  
Evaluation Model ◽  
Sustainable Construction ◽  
Model Parameters ◽  
Recognition Model ◽  
Sample Data ◽  
Index Evaluation ◽  
Fuzzy Recognition

The floods have undermined the sustainable construction of cities because of their sudden and destruction. To reduce the losses caused by floods, it is necessary to make a reasonable evaluation for historical floods and provide scientific guidance for future precaution. Previous research mainly used subjective/objective weights or barely made static analysis without considering the uncertainty and ambiguity of floods. Therefore, this study proposed a variable fuzzy recognition model, based on combined weights, to evaluate floods, including the determination of index weights and the choice of evaluation model. To make the index weights reflect both subjective experience and objective data, the combined weights were proposed and calculated based on the principle of minimum identification information. Then, the relative membership degree matrix and evaluation results can be worked out by the variable fuzzy recognition model. Conclusions indicated that the combined weights were more convincing than simply subjective or objective weights. Moreover, the variable fuzzy recognition model, by changing model parameters, got stable evaluation results of the sample data. Therefore, the model can improve the credibility of evaluation and the conclusions can provide reasonable suggestions for management departments.

scholarly journals The Effect of the Size of Traffic Analysis Zones on the Quality of Transport Demand Forecasts and Travel Assignments

2018 ◽  
Author(s):  
Mehmet Fatih Altan ◽  
Yunus Emre Ayözen
Keyword(s):  
Regression Model ◽  
Traffic Analysis ◽  
Model Parameters ◽  
The Public ◽  
Employment Density ◽  
Exponential Regression Model ◽  
Demand Forecasts

In this work we have studied the selection criteria for traffic analysis zones and the effects of their size and number on the model’s forecasting capabilities. To do so we have focused on the corridor of İstanbul’s Kadıköy-Kartal Metro Line and evaluated the consistency of demand forecasts and travel assignments versus actual measurements under different sizes of the Traffic Analysis Zones (TAZ). Significant improvements in model accuracy were observed by decreasing the zone size. Specifically, studying the public transport network assignments for the metro line when increasing the number of traffic analysis zones from 540 to 1,788 the root mean square error (RMSE) of forecasted vs. actual station-based counts was reduced by 23%. Subsequently, the study used population density and employment density as independent variables for the determination of the optimal radius for the 1,788 zone area, and applied an exponential regression model. Appropriate model parameters were derived for the above case study. The regression model resulted in R2 values over 0.62.

scholarly journals An approach to identify time consistent model parameters: sub-period calibration

2013 ◽  
Vol 17 (1) ◽  
pp. 149-161 ◽  
Author(s):  
S. Gharari ◽  
M. Hrachowitz ◽  
F. Fenicia ◽  
H. H. G. Savenije
Keyword(s):  
Model Performance ◽  
Realistic Model ◽  
Parameter Estimates ◽  
Model Parameters ◽  
New Approach ◽  
Consistent Model ◽  
Set Up ◽  
Consistent Parameter

Abstract. Conceptual hydrological models rely on calibration for the identification of their parameters. As these models are typically designed to reflect real catchment processes, a key objective of an appropriate calibration strategy is the determination of parameter sets that reflect a "realistic" model behavior. Previous studies have shown that parameter estimates for different calibration periods can be significantly different. This questions model transposability in time, which is one of the key conditions for the set-up of a "realistic" model. This paper presents a new approach that selects parameter sets that provide a consistent model performance in time. The approach consists of testing model performance in different periods, and selecting parameter sets that are as close as possible to the optimum of each individual sub-period. While aiding model calibration, the approach is also useful as a diagnostic tool, illustrating tradeoffs in the identification of time-consistent parameter sets. The approach is applied to a case study in Luxembourg using the HyMod hydrological model as an example.

scholarly journals Uncovering the effects of heterogeneity and parameter sensitivity on within-host dynamics of disease: malaria as a case study

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Shade Horn ◽  
Jacky L. Snoep ◽  
David D. van Niekerk
Keyword(s):  
Disease Model ◽  
Robustness Analysis ◽  
Model Parameters ◽  
Local Sensitivity ◽  
Model Predictions ◽  
Weak Points ◽  
Determination Of Parameters ◽  
Associated Variables

Abstract Background The fidelity and reliability of disease model predictions depend on accurate and precise descriptions of processes and determination of parameters. Various models exist to describe within-host dynamics during malaria infection but there is a shortage of clinical data that can be used to quantitatively validate them and establish confidence in their predictions. In addition, model parameters often contain a degree of uncertainty and show variations between individuals, potentially undermining the reliability of model predictions. In this study models were reproduced and analysed by means of robustness, uncertainty, local sensitivity and local sensitivity robustness analysis to establish confidence in their predictions. Results Components of the immune system are responsible for the most uncertainty in model outputs, while disease associated variables showed the greatest sensitivity for these components. All models showed a comparable degree of robustness but displayed different ranges in their predictions. In these different ranges, sensitivities were well-preserved in three of the four models. Conclusion Analyses of the effects of parameter variations in models can provide a comparative tool for the evaluation of model predictions. In addition, it can assist in uncovering model weak points and, in the case of disease models, be used to identify possible points for therapeutic intervention.

3D Linear Identification of Mechanical Joint Using FRF Decoupling and Inverse Structural Modification Methods

2021 ◽  
Author(s):  
Hossein Soleimani ◽  
Ender Cigeroglu ◽  
H. Nevzat Özgüven
Keyword(s):  
Structural Modification ◽  
Model Parameters ◽  
Engineering Structures ◽  
Bolted Connection ◽  
Decoupling Method ◽  
Beam Elements ◽  
Method Formulation ◽  
Joint Parameters

Abstract Mechanical connections such as bolts and rivets are inevitable in most engineering structures and may significantly affect the dynamic behavior of the structures. Therefore, modeling a joint simply and accurately is essential for assembled structures. On the other hand, the most important step is the determination of these joint model parameters which will be used in the calculation of dynamic response of assembled structures. For this purpose, in this paper, FRF Decoupling Method (FRF-DM), proposed in an earlier study for bolted beam connections is extended in two ways: Firstly, the bolt model proposed for 2D beam elements is extended to 3D finite element models of structural systems, and thus the dynamics of a bolted connection is modeled as an equivalent 6 × 6 complex stiffness matrix including linear and torsional stiffnesses. Secondly, FRF-DM is extended to include measurements at connection degrees of freedoms, which improves the accuracy in identification. Several equations for the identification of joint parameters are derived utilizing FRF-DM. Joint parameters are calculated by using developed FRF decoupling relations, as well as by employing a recently developed method called Inverse Structural Modification Method (ISMM) in a case study consisting of two beams connected by a 6 × 6 stiffness and viscous damping matrices. The accuracy and the advantages of each method/formulation are discussed by using the case study based on simulated experiments.

Dynamic Evaluation Model of Enterprise Informatization Level and its Application

2011 ◽  
Vol 201-203 ◽  
pp. 738-743
Author(s):  
Wu Yong Qian ◽  
Yao Guo Dang ◽  
Chen Yu Lin
Keyword(s):  
Time Series ◽  
Evaluation Model ◽  
Matrix Norm ◽  
Dynamic Evaluation ◽  
Enterprise Informatization ◽  
Evaluation Models ◽  
The Difference ◽  
Static Evaluation

The existing evaluation models of enterprise informatization level are mostly static evaluation model. And they can’t meet the need of dynamic evaluation of enterprise informatization level. According to the principle of priority information, this paper proposes a new method to determine time series weights based on matrix norm. By using the driving principle of the difference, this paper gives a determination of index weights. And based on time series weights and determination of index weights, the paper establishes a dynamic evaluation model of enterprise informatization level, and gives the calculation steps. Through the case study, this paper tests the validity of the model.

scholarly journals Moving beyond traditional model calibration or how to better identify realistic model parameters: sub-period calibration

2012 ◽  
Vol 9 (2) ◽  
pp. 1885-1918
Author(s):  
S. Gharari ◽  
M. Hrachowitz ◽  
F. Fenicia ◽  
H. H. G. Savenije
Keyword(s):  
Model Calibration ◽  
Model Performance ◽  
Realistic Model ◽  
Parameter Estimates ◽  
Model Parameters ◽  
New Approach ◽  
Consistent Model ◽  
Set Up

Abstract. Conceptual hydrological models often rely on calibration for the identification of their parameters. As these models are typically designed to reflect real catchment processes, a key objective of an appropriate calibration strategy is the determination of parameter sets that reflect a "realistic" model behavior. Previous studies have shown that parameter estimates for different calibration periods can be significantly different. This questions model transposability in time, which is one of the key conditions for the set-up of a "realistic" model. This paper presents a new approach that selects parameter sets that provide a consistent model performance in time. The approach consists of confronting model performance in different periods, and selecting parameter sets that are as close as possible to the optimum of each individual sub-period. While aiding model calibration, the approach is also useful as a diagnostic tool, illustrating tradeoffs in the identification of time consistent parameter sets. The approach is demonstrated in a case study where we illustrate the multi-objective calibration of the HyMod hydrological model to a Luxembourgish catchment.

A novel method for the determination of linting propensity of paper

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD
Keyword(s):  
Ash Content ◽  
The Novel ◽  
Offset Printing ◽  
Excellent Correlation ◽  
End Conditions ◽  
Bottom Side ◽  
Novel Method ◽  
Total Fraction

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.

The Calculation of Turbulent Diffusion Coefficients in Aquatic Ecosystems

2019 ◽  
Vol 70 (11) ◽  
pp. 3903-3907
Author(s):  
Galina Marusic ◽  
Valeriu Panaitescu
Keyword(s):  
Transport Equation ◽  
Turbulent Diffusion ◽  
Diffusion Coefficients ◽  
Aquatic Ecosystems ◽  
Specific Area ◽  
Left Bank ◽  
The Right ◽  
Prut River

The paper deals with the issues related to the pollution of aquatic ecosystems. The influence of turbulence on the transport and dispersion of pollutants in the mentioned systems, as well as the calculation of the turbulent diffusion coefficients are studied. A case study on the determination of turbulent diffusion coefficients for some sectors of the Prut River is presented. A new method is proposed for the determination of the turbulent diffusion coefficients in the pollutant transport equation for specific sectors of a river, according to the associated number of P�clet, calculated for each specific area: the left bank, the right bank and the middle of the river.

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