A multi-objective evolutionary optimisation model for heterogeneous vehicles routing and relief items scheduling in humanitarian crises

In a disaster scenario, relief items distribution is required as early as possible for the disaster victims to reduce the associated risks. For the distribution tasks, an effective and efficient relief items distribution model to generated relief items distribution schedules is essential to minimise the impact of disaster to the disaster victims. However, developing efficient distribution schedules is challenging as the relief items distribution problem has multiple objectives to look after where the objectives are mostly contradictorily creating a barrier to simultaneous optimisation of each objective. Also, the relief items distribution model has added complexity with the consideration of multiple supply points having heterogeneous and limited vehicles with varying capacity, cost and time. In this paper, multi-objective evolutionary optimisation with the greedy heuristic search has been applied for the generation of relief items distribution schedules under heterogeneous vehicles condition at supply points. The evolutionary algorithm generates the disaster region distribution sequence by applying a global greedy heuristic search along with a local search that finds the efficient assignment of heterogeneous vehicles for the distribution. This multi-objective evolutionary approach provides Pareto optimal solutions that decision-makers can apply to generate effective distribution schedules that optimise the distribution time and vehicles’ operational cost. In addition, this optimisation also incorporated the minimisation of unmet relief items demand at the disaster regions. The optimised distribution schedules with the proposed approach are compared with the single-objective optimisation, weighted single-objective optimisation and greedy multi-objective optimisation approaches. The comparative results showed that the proposed multi-objective evolutionary approach is an efficient alternative for finding the distribution schedules with optimisation of distribution time and operational cost for the relief items distribution with heterogeneous vehicles

Click for updates Molecular Physics: An International Journal at the Interface Between Chemistry and Physics A computational perspective on the kinetics and thermochemistry of the gas phase reactions of 1, 1- dichlorodimethylether (DCDME) with OH radical

Kinetics and thermochemistry of the gas phase reactions between CH 3 OCHCl 2 (DCDME) and OH radical are investigated theoretically. The geometries and all the stationary points on the potential energy surface are calculated at BHandHLYP/6-311G(d,p) method. The energy information is further refined at CCSD(T)/6-311G(d,p) level of theory. Reaction profiles are modelled including the formation of two pre-reactive and post-complexes. The rate constants, which are evaluated by Canonical Transition State Theory (CTST) including tunnelling correction at 298 K, are in very good agreement with the available experimental data. The percentage contributions of both reaction channels are also reported at 298 K. The hydrogen abstraction reaction from the -CHCl 2 group is found to be dominant leading to the formation of CH 3 OCCl 2 + H 2 O. Using group-balanced isodesmic reactions, the standard enthalpies of formation for CH 3 OCHCl 2 , CH 3 OCCl 2 and CH 2 OCHCl 2 are also reported

Theoretical studies on decomposition kinetics of CF₃CF₂O radical

1167-1173The unimolecular decomposition reactions of CF3CF2O radical formed from hydrofluorocarbons, CF3CHF2 in the atmosphere has been investigated using ab initio quantum mechanical methods. Two most important channels of decomposition occurring via C-C bond scission and F-elimination have been considered. Energetics calculations have been performed at G2(MP2) and G2M(CC,MP2) level of theories. The calculations reveal that C-C bond scission is the dominant pathway during the decomposition of CF3CF2O radical. Transition states have been searched on the potential energy surface of the decomposition reactions involved. Intrinsic reaction coordinate calculations have also been made. The analysis shows that transition states smoothly connect the reactant and products. The thermal rate constants for the decomposition reactions involved are evaluated using Canonical transition state theory utilizing the ab initio data at 298 K and 1 atm pressure

A two-phase confirmatory factor analysis and structural equation modelling for customer-based brand equity framework in the smartphone industry

The emergence of smartphones has brought a transformative change in the smartphone industry in terms of technological innovations and business decision-making dynamics. Smartphones have appeared in the market as the standard configuration and currently represent the fastest-growing market segment in the telecommunications industry. It is considered a highly involved product that is relevant and important to the buyer due to its daily use and multiple functionalities. With this growth in smartphone use, the market has been more competitive with the emergence of new brands leading to a wide range of brand selection opportunities for customers. Therefore, there is a need for smartphone companies to understand customers’ brand equity before implementing strategic decision-making to promote their brands. This paper introduces a conceptual framework based on the theoretical framework of Keller and Aakar’s Customer-Based Brand Equity (CBBE) models. This conceptual framework consists of nine constructs organised into three layers: marketing programs, brand equity dimensions, and brand equity. The framework has been validated using a quantitative survey of Nepalese smartphone users in two phases. In the first phase, Exploratory Factor Analysis (EFA) has been performed to measure the reliability of the constructs and the Factor Loading (FL) of the scales under each construct of the proposed framework. In the second phase, the survey questionnaire has been revised based on the analytical results of the first phase, and the full-phase survey has been conducted. The full-scale survey data has been analysed using Confirmatory Factor Analysis (CFA). Hence, the relationship between the constructs has been measured using Structural Equation Modeling (SEM) for the proposed framework. This proposed framework has focused on different strategic decision-making constraints of smartphone marketing, which decision-makers can utilise to develop market policies and other business decisions. The results have indicated that the Product Features (PF) have an important role in creating positive Perceived Quality (PQ) if the promotion has been made to create Brand Awareness (BA). Positive PQ helps in enhancing Brand Image (BI). Marketers need to focus on creating positive Brand Preference (BP), as BI is not sufficient in creating Brand Loyalty (BL) and Brand Repurchase (BR)

A Theoretical Investigation on Kinetics, Mechanism, and Thermochemistry of the Gas-Phase Reactions of Methyl Fluoroacetate with OH Radicals and Fate of Alkoxy Radical

We theoretically investigated OH-initiated hydrogen abstraction reactions of methyl fluoroacetate (MFA) CH₂FC­(O)­OCH₃ at the MPWB1K level of theory in conjunction with the 6-31+G­(d,p) basis set. Thermodynamic and kinetic data are computed using the comparatively accurate G2­(MP2) method. Two most stable conformers of MFA are identified, and the energy difference between them is found to be only 0.32 kcal mol^–1. Both of them are considered for rate coefficient calculations, and the contribution from each of the conformers is found to be quite significant. We propose an indirect mechanism due to validation of pre- and post-reactive complexes. The rate parameters are determined using canonical transition state theory and energetics at the G2­(MP2) level. The temperature dependence of the rate constant can be described by the Arrhenius expressions: <i>k</i> = 8.79 × 10^–13 exp[(−377.27 ± 64)/<i>T</i>] cm³ molecule^–1 s^–1 over a temperature range of 250–450 K. The Δ_f<i>H</i>°₂₉₈ for CH₂FC­(O)­OCH_3, CH₂FC­(O)­OC^•H₂, and C^•HFC­(O)­OCH₃ are also computed using an isodesmic procedure. The OH-driven atmospheric lifetime of MFA was estimated to be 24 days. A mechanistic study to shed light on the atmospheric degradation and the sole fate for the consumption of CH₂FC­(O)­OCH₂O^• radical has also been reported

Silicone tracheobronchial stent: A rare cause for bronchoesophageal fistula and distortion of airway anatomy

Silicone tracheobronchial stents are being increasingly used in a large number of patients for the treatment of tracheal stenosis. One very rare complication due to tracheobronchial stenting is bronchoesophageal fistula (BEF), which has been associated with the use of metallic stents. We report intraoperative management of a patient undergoing repair of a BEF, following previous insertion of a silicone Y-stent that is soft in texture and has not been implicated for this complication till date. In addition, misalignment of this silicone tracheobronchial Y-stent resulted in a tracheal mucosal bulge proximal to the stent that vanished after its removal

From Raising Awareness to a Behavioural Change: A Case Study of Indoor Air Quality Improvement Using IoT and COM-B Model

The topic of indoor air pollution has yet to receive the same level of attention as ambient pollution. We spend considerable time indoors, and poorer indoor air quality affects most of us, particularly people with respiratory and other health conditions. There is a pressing need for methodological case studies focusing on informing households about the causes and harms of indoor air pollution and supporting changes in behaviour around different indoor activities that cause it. The use of indoor air quality (IAQ) sensor data to support behaviour change is the focus of our research in this paper. We have conducted two studies—first, to evaluate the effectiveness of the IAQ data visualisation as a trigger for the natural reflection capability of human beings to raise awareness. This study was performed without the scaffolding of a formal behaviour change model. In the second study, we showcase how a behaviour psychology model, COM-B (Capability, Opportunity, and Motivation-Behaviour), can be operationalised as a means of digital intervention to support behaviour change. We have developed four digital interventions manifested through a digital platform. We have demonstrated that it is possible to change behaviour concerning indoor activities using the COM-B model. We have also observed a measurable change in indoor air quality. In addition, qualitative analysis has shown that the awareness level among occupants has improved due to our approach of utilising IoT sensor data with COM-B-based digital interventions

A computational perspective on the kinetics and thermochemistry of the gas phase reactions of 1, 1-dichlorodimethylether (DCDME) with OH radical at 298 K

<p>Kinetics and thermochemistry of the gas phase reactions between CH₃OCHCl₂ (DCDME) and OH radical are investigated theoretically. The geometries and all the stationary points on the potential energy surface are calculated at BHandHLYP/6-311G(d,p) method. The energy information is further refined at CCSD(T)/6-311G(d,p) level of theory. Reaction profiles are modelled including the formation of two pre-reactive and post-complexes. The rate constants, which are evaluated by Canonical Transition State Theory (CTST) including tunnelling correction at 298 K, are in very good agreement with the available experimental data. The percentage contributions of both reaction channels are also reported at 298 K. The hydrogen abstraction reaction from the –CHCl₂ group is found to be dominant leading to the formation of CH₃OCCl₂ + H₂O. Using group-balanced isodesmic reactions, the standard enthalpies of formation for CH₃OCHCl₂, CH₃OCCl₂ and CH₂OCHCl₂ are also reported.</p