scholarly journals A Hybrid Approach Integrating Entropy-AHP and GIS for Suitability Assessment of Urban Emergency Facilities

2020 ◽  
Vol 9 (7) ◽  
pp. 419
Author(s):  
Penjani Hopkins Nyimbili ◽  
Turan Erden
Keyword(s):  
Sensitivity Analysis ◽  
Hybrid Approach ◽  
Fire Service ◽  
Facility Planning ◽  
Project Area ◽  
Suitability Assessment ◽  
Urban Fire ◽  
Suitability Map ◽  
Urban Fires ◽  
Service Coverage

Globalization has become a major issue of focus as rapid urban populations and urbanization effects are on the rise. A critical need arises for effective urban planning for Istanbul in relation to the use of a hybrid approach integrating AHP-Entropy and GIS for emergency facility planning. In this paper, the combination of AHP and Entropy methods was used for evaluating criterion weights subjectively and objectively. These techniques were utilized with regard to the assessment of suitable areas for planning new urban emergency facilities for Istanbul province which experiences increasing urban fire-related emergencies. AHP and Entropy have been used to evaluate the weights of determined criteria from expert preference judgments and GIS for processing, analysis and visualization of the model result in the form of a suitability map for new urban emergency facilities. Validation of the model was performed on the criteria with the strongest influence in the decision outcome and spatially visualized using the sensitivity analysis (SA) method of one-at-a-time (OAT). From the findings, it was estimated that 28.1% of the project area, accounting for a third of it, is likely to be exposed to the risk of urban fires and therefore immediate planning of new urban emergency facilities is recommended for adequate fire service coverage and protection.

A multi-objective optimization approach for simultaneously lightweighting and maximizing functional performance of vehicle body structure

2019 ◽  
Vol 234 (7) ◽  
pp. 2086-2102
Author(s):  
Dengfeng Wang ◽  
Shuang Wang ◽  
Chong Xie
Keyword(s):  
Genetic Algorithm ◽  
Sensitivity Analysis ◽  
Hybrid Approach ◽  
Support Vector ◽  
Ideal Solution ◽  
Analysis Method ◽  
Multi Objective ◽  
Sensitivity Analysis Method ◽  
Order Preference ◽  
Pillar Structure

This study presents a hybrid approach to integrate the comprehensive sensitivity analysis method, support vector machine technology, modified non-dominated sorting genetic algorithm-II method and the technique for order preference by similarity to ideal solution, which have been applied to multi-objective lightweight optimization of the B-pillar structure of an automobile. First, numerical models of the static–dynamic stiffness and the crashworthiness performance of automobile are established and validated by experimental testing. Then, the comprehensive sensitivity analysis method is used to define the final optimization variables. Experimental design and support vector machine based surrogate model techniques are introduced to establish the approximate model; subsequently, the modified non-dominated sorting genetic algorithm-II algorithm is applied to the multi-objective lightweight optimization design of the B-pillar structure, and the non-dominated solution set is determined. The principal component analysis method is applied to determine the weight of each objective. Finally, the technique for order preference by similarity to ideal solution method is used to rank Pareto front from best to worst to obtain the optimal solution; furthermore, a comparison between the original model and optimized design denotes that the mass of the B-pillar being reduced by 22.55% under the other impacting indicators is well guaranteed. Therefore, the proposed hybrid approach provided promising prospects in the lightweight and crashworthiness optimization application of the B-pillar.

scholarly journals P427 A hybrid approach of handling missing data in inflammatory bowel disease (IBD) trials: results from VISIBLE 1 and VARSITY

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S388-S389
Author(s):  
J Chen ◽  
S Hunter ◽  
K Kisfalvi ◽  
R A Lirio
Keyword(s):  
Sensitivity Analysis ◽  
Missing Data ◽  
Statistical Power ◽  
Hybrid Approach ◽  
Missing At Random ◽  
P Value ◽  
Two Phase ◽  
Treatment Difference ◽  
Mayo Score ◽  
The Impact

Abstract Background Missing data is common in IBD trials. Depending on the volume and nature of missing data, it can reduce statistical power for detecting treatment difference, introduce potential bias and invalidate conclusions. Non-responder imputation (NRI), where patients (patients) with missing data are considered treatment failures, is widely used to handle missing data for dichotomous efficacy endpoints in IBD trials. However, it does not consider the mechanisms leading to missing data and can potentially underestimate the treatment effect. We proposed a hybrid (HI) approach combining NRI and multiple imputation (MI) as an alternative to NRI in the analyses of two phase 3 trials of vedolizumab (VDZ) in patients with moderate-to-severe UC – VISIBLE 11 and VARSITY2. Methods VISIBLE 1 and VARSITY assessed efficacy using dichotomous endpoints based on complete Mayo score. Full methodologies reported previously.1,2 Our proposed HI approach is aimed at imputing missing Mayo scores, instead of imputing the missing dichotomous efficacy endpoint. To assess the impact of dropouts for different missing data mechanisms (categorised as ‘missing not at random [MNAR]’ and ‘missing at random [MAR]’, HI was implemented as a potential sensitivity analysis, where dropouts owing to safety or lack of efficacy were imputed using NRI (assuming MNAR) and other missing data were imputed using MI (assuming MAR). For MI, each component of the Mayo score was imputed via a multivariate stepwise approach using a fully conditional specification ordinal logistic method. Missing baseline scores were imputed using baseline characteristics data. Missing scores from each subsequent visit were imputed using all previous visits in a stepwise fashion. Fifty imputation datasets were computed for each component of Mayo score. The complete Mayo score and relevant efficacy endpoints were derived subsequently. The analysis was performed within each imputed dataset to determine treatment difference, 95% CI and p-value, which were then combined via Rubin’s rules3. Results Tables 1 and 2 show a comparison of efficacy in the two studies using the primary NRI analysis vs. the alternative HI approach for handling missing data. Conclusion HI and NRI approaches can provide consistent efficacy analyses in IBD trials. The HI approach can serve as a useful sensitivity analysis to assess the impact of dropouts under different missing data mechanisms and evaluate the robustness of efficacy conclusions. Reference

scholarly journals Applying Real-Time Travel Times to Estimate Fire Service Coverage Rate for High-Rise Buildings

2020 ◽  
Vol 10 (19) ◽  
pp. 6632
Author(s):  
Dingli Liu ◽  
Zhisheng Xu ◽  
Long Yan ◽  
Feiyue Wang
Keyword(s):  
Real Time ◽  
Fire Service ◽  
Time Travel ◽  
Coverage Rate ◽  
Travel Times ◽  
Estimation Model ◽  
Effective Coverage ◽  
High Rise ◽  
High Rise Building ◽  
Service Coverage

Frequent high-rise building fires have posed serious threats to urban public safety. In this study, real-time travel times extracted from online maps were applied to estimate fire service coverage rates for high-rise buildings. Firstly, the minimum fire apparatus requirement for high-rise building “at least 1 water fire truck and 1 aerial fire truck should arrive at the fire scene of high-rise building within 240 s” was proposed. Then, a dynamic estimation model of fire service coverage rate for high-rise buildings was established. To validate the model, 5146 high-rise buildings, 61 water fire trucks, and 56 aerial fire trucks in Changsha were selected as case studies. The results show that the total effective coverage rate and total average travel time in Changsha are 20.43% and 421.95 s, respectively. There are 10,840 water fire trucks and 6192 aerial fire trucks in China. Based on the average number of water fire trucks and aerial fire trucks per high-rise building, it can be estimated that the total effective coverage rate in China may not exceed 60.00%. Due to limited fire resources and frequent traffic congestion, only partial high-rise buildings can be effectively covered by fire services, whether in Changsha or China.

scholarly journals Assessing Ecosystem and Urban Services for Landscape Suitability Mapping

2021 ◽  
Vol 11 (17) ◽  
pp. 8232
Author(s):  
Sara Antognelli ◽  
Marco Vizzari
Keyword(s):  
Sensitivity Analysis ◽  
Landscape Planning ◽  
Well Being ◽  
Assessment Model ◽  
Policy Makers ◽  
Spatial Indices ◽  
Urban Services ◽  
Suitability Assessment ◽  
Landscape Suitability ◽  
Different Characteristics

Ecosystem services (ES) and urban services (US) can comparably improve human well-being. Models for integrating ES and US with unexpressed and objective needs of defined groups of stakeholders may prove helpful for supporting decisions in landscape planning and management. In fact, they could be applied for highlighting landscape areas with different characteristics in terms of services provided. From this base, a suitability spatial assessment model (SUSAM) was developed and applied in a study area considering different verisimilar scenarios that policy makers could analyse. Each scenario is based on the prioritization of a set of services considering a defined group of stakeholders. Consistent and comparable ES and US indices of spatial benefiting areas (SBA) of services were calculated using GIS spatialization techniques. These indices were aggregated hierarchically with the relevance of services according to a spatial multicriteria decision analysis (S-MCDA). Results include maps for each scenario showing detailed spatial indices of suitability that integrate the local availability of SBA of ES and US, along with their relevance. The results were compared with known landscape classes identified in previous studies, which made it possible to interpret the spatial variation of suitability in the light of known landscape features. A complete sensitivity analysis was performed to test the sensitiveness of the model’s outputs to variations of judgements and their resistance to the indicators’ variation. The application of the model demonstrated its effectiveness in a landscape suitability assessment. At the same time, the sensitivity analysis and helping to understand the model behaviour in the different landscape classes also suggested possible solutions for simplifying the whole methodology.

Urban Fire as an Unstabilized Parasite: The 1976–1978 Outbreak in Bushwick, Brooklyn

1983 ◽  
Vol 15 (2) ◽  
pp. 207-226 ◽  
Author(s):  
R Wallace ◽  
D Wallace
Keyword(s):  
New York ◽  
Life Cycle ◽  
Fire Service ◽  
Rand Corporation ◽  
Urban Fire ◽  
Parasite Infestation ◽  
Temporal And Spatial ◽  
In Fire ◽  
Parasite Populations ◽  
Fire Outbreak

Fire service cuts recommended by the Rand Corporation, and largely implemented before New York City's ‘fiscal crisis’, are known to have initiated a geographically spreading, temporally recurrent fire epidemic. Examination of a resulting fire outbreak in Brooklyn's Bushwick section shows the epidemic to have temporal and spatial ‘patchiness' characteristics of a parasite infestation, as well as an apparent composite ‘life cycle’, but without the stabilizing mechanisms which assure the survival both of host and of parasite populations. The composite fire ‘life cycle’ implies the need for a multiple factor eradication program, in which improvements in fire service play a key role, both for extinguishment and for prevention purposes.

scholarly journals Methodical Aspects of MCDM Based E-Commerce Recommender System

2021 ◽  
Vol 16 (6) ◽  
pp. 2192-2229
Author(s):  
Aleksandra Bączkiewicz ◽  
Bartłomiej Kizielewicz ◽  
Andrii Shekhovtsov ◽  
Jarosław Wątróbski ◽  
Wojciech Sałabun
Keyword(s):  
Sensitivity Analysis ◽  
Hybrid Approach ◽  
Correlation Coefficients ◽  
Central Component ◽  
Weighting Method ◽  
Product Comparison ◽  
Ranking Of Alternatives ◽  
Mcdm Method ◽  
Main Component ◽  
Suitable Product

The aim of this paper is to present the use of an innovative approach based on MCDM methods as the main component of a consumer Decision Support System (DSS) by recommending the most suitable products among a given set of alternatives. This system provides a reliable recommendation to the consumer in the form of a compromise ranking constructed from the five MCDM methods: the hybrid approach TOPSIS-COMET, COCOSO, EDAS, MAIRCA, and MABAC. Each of the methods used contributes significantly to the final compromise ranking built with the Copeland strategy. Chosen MCDM methods were combined with the objective CRITIC weighting method, and their performance was presented on the illustrative example of choosing the most suitable mobile phone. A sensitivity analysis involving the rw and WS correlation coefficients was performed to determine the match between the compromise ranking of the candidates and the rankings provided by each MCDM method. Sensitivity analysis demonstrated that all investigated compromise candidate rankings show high convergence with the rankings provided by the particular MCDM methods. Thus, the performed study proved that the proposed approach shows high potential to be successfully used as a central component of DSS for recommending the most suitable product. Such DSS could be a universal and future-proof solution for e-commerce sites and websites, providing advanced product comparison capabilities in delivering a recommendation to the user as a final ranking of alternatives.

A hybrid approach for the sensitivity analysis of integrated inductors

Integration ◽  
2016 ◽  
Vol 52 ◽  
pp. 237-242 ◽  
Author(s):  
A. Sallem ◽  
P. Pereira ◽  
M. Helena Fino ◽  
M. Fakhfakh
Keyword(s):  
Sensitivity Analysis ◽  
Hybrid Approach ◽  
Integrated Inductors
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