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With the advancements in electric vertical take-off and landing (eVTOL) aircraft technology such as batteries, mechanisms, motors, configurations and so on, designers and engineers are encouraged to create unique and unconventional configurations of eVTOL aircraft to provide better capabilities and higher efficiencies to compete in the market. The box fan-in-split-wing tiltrotor eVTOL aircraft is an innovative design that aims to address the aerodynamic inefficiencies such as propeller effects in cruise and engine mounts drag that existed in traditional eVTOL aircraft designs such as vectored thrust, rotorcraft, lift + cruise and multi-copter configurations. This paper aims to propose a multi-disciplinary design process to conceptually design the box fan-in-split-wing Tiltrotor eVTOL aircraft.

An unconventional methodology was used to design the UAM aircraft, and the following parameters are considered: capable of vertical take-off and landing, highly aerodynamic with a high lift-to-drag ratio, low Cd₀ modern and appealing, rechargeable or battery swappable and feature to minimise or negate propeller drag. A heavy emphasis on improving performance and weight based on aerodynamics was enforced during the conceptual design phase. MAPLA and XFOIL were used to identify the aerodynamic properties of the aircraft.

Upon determining the key parameters and the mission requirements and objectives, a list of possible VTOL configurations was derived from theoretical and existing designs. The fan in the wing/split wing was selected, as it could stow the propellers. A tiltrotor configuration was selected because of its ability to reduce the total number of lift props/motors, reducing powerplant weight and improving aerodynamic efficiency. For the propulsion configuration, a battery–motor configuration with a hexa-rotor layout was chosen because of its ability to complement the planform of the aircraft, providing redundant motors in case of failure and because of its reliability, efficiency and lack of emissions. Coupled with the fan-in-wing / split wing concept, the box wing seamlessly combines all chosen configurations.

The box fan-in-split-wing Tiltrotor eVTOL aircraft aims to address the aerodynamic inefficiencies of earlier designs such as propeller effects in cruise and engine mounts drag. The potential benefits of this aircraft, such as increased range, endurance and payload capacity, make it an exciting prospect in the field of Urban Air Mobility.

The purpose of this paper is to propose a saturable model based on the magnetic equivalent circuit (MEC) for evaluating the electromagnetic performance of the variable area resolver.

The equivalent circuit is developed where three different reluctance types are used to calculate permeances based on geometrical approximations. The proposed model typically has two types of equations, including the magnetic and electrical equations. The magnetic and electrical equations are related to the resolver core and the windings, respectively. Applying the well-known trapezoidal method, the magnetic and electrical equations can be simultaneously solved. A nonlinearity of the magnetic equations, the algebraic equations system, which is obtained from Kirchhoff’s laws, should be solved by the Newton-Raphson technique in each step-time.

The flexible MEC model, in which the number of flux tubes in different parts of the resolver can be arbitrarily selected, is proposed to analyze the variable reluctance resolver. Besides, the design parameters such as geometrical dimensions, windings arrangement and a number of the rotor saliencies can be chosen as desired. To consider the effect of time harmonics, a new nonlinear function is used for the core magnetization. Furthermore, different winding layouts can be implemented in the model to take space harmonics into account. The model obtained results are compared with the finite element method in terms of accuracy and simulation time.

Generally, the accuracy of the predictions in the MEC method is dependent on the number of flux tubes; therefore, the flexibility of the proposed MEC model in its capability to choose the desired number of flux paths is the advantage of this work. Moreover, the proposed model can analyze both wound and saliency rotor resolvers by changing the design parameters.

Each production unit is responsible for the protection of the environment. The restricted undesirable production effects lower environmental damage. This paper emphasizes a proportional reduction of the undesirable outputs, and it supports the growth of desirable outputs as much as possible as well. The two-stage proposed model not only considers the viewpoint of the managers to follow the environmental regulations but also it assigns some bounds on producing undesirable factors according to international environmental protocols. Additionally, the restricted bounds on the undesirable outputs, in both stages, enhance the discriminatory ability of the model.

Two-stage network structure based on Data Envelopment Analysis (DEA) is applied as the main methodology for this paper. The advantages of the proposed model are appointed to assess the environmental units.

Comparing with the existing models, the proposed approach presents a new two-stage model to deal with the environmental issues. Furthermore, the discriminatory ability of the efficiency scores is improved. The distribution of this model is greater than the existing ones.

This paper is fully written, submitted and revised during limitations caused by coronavirus .

The proposed method is employed in two different cases. The efficiency scores of 25 power plants and 13 poultry farms are determined. In fact, the undesirable outputs never meet zero in the process of production but they can be reduced. The results of this research support the effect of the undesirable factors' restriction on the reduction scenario. Both of the examples show that imposing the upper bounds for the undesirable products provide low-efficiency results in comparison with the existing model. On the other hand, the results cover the arguments of sustainability in the evaluation of environmental efficiency.

In the production process, desirable outputs and undesirable factors are produced jointly so undesirable factors never meet zero. This paper develops a new two-stage method to reduce the undesirable outputs at each stage. First, the model confirms the reduction of undesirable outputs. Second, this model imposes restrictions on intermediate and final undesirable outputs according to environmental rights and the concerns of the managers. The model increases the discrimination of the efficiency assessment of real-life two-stage environmental systems as well. Then it focuses on the production of desirable outputs. The new objective function is defined according to the aim of the proposed model that not only declares better efficiency decomposition to the individual system but also the efficiency score is evaluated for each stage.

The ground control station (GCS) is an important part of unmanned aerial vehicles (UAVs) which provides the facility for human control. In previous work, the authors developed an enhanced virtual reality GCS (VR-GCS) for airships. Here, the authors incorporated haptic gloves to control the aerial vehicle with the use of a virtual controller defined within the virtual environment.

The VR headset was connected to the haptics and the flight simulation tool. The VR headset was used to visualize basic flight simulation while the vehicle was controlled via the haptic gloves and a virtual controller defined in the virtual environment. Here, using the previous experience, the position and orientation data from the VR headset was sent to the FlightGear flight simulator (FGFS) via extensible markup language codes. This was used to drive the heads-up-display (HUD) as well within the VR headset. Then, the inputs from the pilot on the virtual controller were sent to the FGFS using an embedded code. To accurately simulate the final goal of deploying the haptic-based VR solution to monitor and pilot the airship in beyond visual line-of-sight scenarios, a VR application was developed using the Unity game engine. Finally, the integration of VR, haptics and FGFS was performed using another embedded code.

A test procedure was conducted with a similar rating technique based on the NASA TLX questionnaire that identifies the pilot’s spare mental capacity when completing an assigned task to assure the comfortability of the proposed haptics VR-HMD (HVR-HMD). Accordingly, 10 users participated in the test and a comparison has been made for the aircraft control using the physical remote control (RC) controller and the virtual one. The results from the repeated measures analysis of variance and Tukey’s honestly significant difference post hoc tests revealed significant differences in mental demand, physical demand, effort and frustration across the different simulation conditions. Notably, the HVR-HMD system significantly lowered workload and frustration levels compared to both the desktop and VR-HMD setups, underscoring its effectiveness as a training tool. Results from the NASA TLX questionnaire showed that the current iteration of the system is ideal for training amateur users to replace traditional RC controllers by using similar virtual systems in a safe and immersive environment.

Such an advanced portable system may increase the situational awareness of pilots and allow them to complete flights with the same data transmission procedures using virtual systems in simulation.

The aim of this paper is to propose the model for analyzing the electromagnetic performances of permanent magnet vernier machines (PMVMs) under healthy and faulty conditions.

The model uses interconnected reluctance network formed based on the geometrical approximations to predict magnetic performances of the machine. The network consists of several types of reluctances for modeling different parts of machine. Applying Kirchhoffs laws in the network and the machine windings, magnetic and electrical equations are obtained, respectively. To construct the model system of equations, the electrical equation is converted into algebraic form by using the trapezoidal technique. Moreover, the system of equations must be solved by Newton–Raphson method in each step-time because of considering the core saturation effect.

The proposed model is developed based on the modified magnetic equivalent circuit (MEC) method, in which the number of flux paths in different parts of the machine can be arbitrary selected. The saturation effect, skewed slots, the desired machine geometrical parameters and various winding arrangements are included in the proposed model; therefore, it can evaluate the time and space harmonics in modeling the PMVMs. Furthermore, a pattern for inter-turn fault detection is extracted from the stator current spectrum. Finally, 2 D-finite element method (FEM) and 3 D-FEM analysis are carried out to evaluate and verify the results of the proposed MEC model.

Generally, the element numbers have important role in modeling the machine and calculating its performance. Hence, the proposed MEC model’s capability to choose desired number of flux paths is advantage of this paper. Moreover, the developed MEC can be used for analyzing several electrical machines, including other types of vernier machines, with simple modification.

The purpose of this paper is to investigate the effect of different PHS on the surface chemistry of fumed silica treated with aminopropyltrimethoxysilane (APTMS).

The reaction conditions involved variation of pH ranging from acidic to alkaline. Different analytical techniques including FT‐IR spectroscopy, thermogravimetric analysis (TGA), CHN and Zeta potential analyses were employed to investigate the surface chemistry of treated particles. In addition, the stability of silanised silica dispersions were studied using turbidimetric and rheometric measurements.

It was revealed that in all conditions silica was more or less chemically grafted by the silane. When the pH of treating bath was adjusted to 1‐2 prior and during the reaction, 58 percent grafting was observed, as obtained by CHN and TGA analyses. At very alkaline conditions, however, the grafting content declined to 29 percent. The variations in grafting were dependent on the silane hydrolysis and its further condensation with the silica surface. Zeta potential measurements showed a drastic change from −7.1 mv to +18.01 mv (at pH 7) for the untreated particle and the one with the highest grafting, respectively. The dispersion stability of differently treated particles varied in solvents with different Hansen solubility parameters (HSP). Moreover, due to the variations of surface chemistry of particles, their rheological behaviours were significantly influenced.

The results obtained in this work showed that the surface chemistry of fume silica could be tuned with treating method. The highest content of grafting led to a better dispersion in solvents having greater hydrogen bonding component and to an inferior dispersion in solvents with higher polar component.

This study aims to explore the intricate relationship between housing prices and transaction volumes in Tehran, a city with diverse socioeconomic and regional characteristics. This research addresses a critical gap in understanding the role of local spatial factors, which previous studies have often overlooked, focusing instead on macroeconomic variables.

Using a data set of housing transactions of Metropolitan Tehran from 2010 to 2020 sourced from secondary data, this study uses generalized linear mixed models and spatial clustering techniques. These methods enable an examination of geographical clustering and the effects of local contextual variables on the dynamics between housing prices and transaction volumes.

Results indicate significant spatial heterogeneity within Tehran’s housing market. Higher prices and transaction volumes are concentrated in the northern and western regions, influenced by factors such as employment rates, rental housing supply and the physical attributes of the housing stock. The findings suggest that macroeconomic policies alone are insufficient to address housing challenges in Tehran; targeted, localized interventions are necessary.

This study’s reliance on secondary data and its focus on a single urban environment may limit the generalizability of the findings. Further research incorporating a wider range of local and macro variables could strengthen the applicability of the results across different contexts.

This study underscores the need for region-specific housing policies that consider local economic, social and spatial conditions. Policymakers could improve housing affordability and accessibility in Tehran by implementing tailored strategies to address the distinct needs of different districts.

This study offers a novel perspective by integrating spatial and contextual factors in housing market analysis, providing insights that challenge the traditional macroeconomic focus. The use of advanced statistical and spatial analysis techniques contributes to a deeper understanding of urban housing market dynamics.

Industrialized construction has brought about expectations of improved productivity in the construction industry. However, the lack of a commonly accepted definition has created confusion regarding the types of development covered by the industrialized construction umbrella. These inconsistent definitions convoluted the discussion on this phenomenon. This study aims to clarify the definition of industrialized construction through a systematic literature review.

This systematic literature review was conducted according to PRISMA principles. Records were gathered from Scopus and Web of Science. Following the scientometric analysis, content analysis was conducted according to the template analysis approach.

The analysis of 121 articles revealed four main themes related to industrialized construction: 1) the construction concept, 2) construction methodologies, 3) systematization, rationalization and automatization and 4) societal and industrial change processes. Definitions of industrialized construction can be analyzed with seven clusters: 1) prefabrication, 2) standardization, 3) sector, 4) integration, 5) manufacturing practices, 6) technological investment and 7) none. Based on the content analysis, the proposed definition is: industrialized construction is the adoption of practices that minimize project-specific work in construction from the start of the design to the end of the building’s life cycle.

This study proposes a definition for industrialized construction following content analysis of broadly sampled literature. The proposed definition can provide a basis on which developments in the construction industry can be reflected.

Construction projects involve with various risks during all phases of project lifecycle. Failure mode and effective analysis (FMEA) is a useful tool for identifying and eliminating possible risk of failure modes (FMs) and improving the reliability and safety of systems in a broad range of industries. The traditional FMEA method applies risk priority number method (RPN) to calculate risk of FMs. RPN method cannot consider the direct and indirect interdependencies between the FMs and is not appropriate for complex system with numerous components. The purpose of this study is to propose an approach to consider interdependencies between FMs and also using fuzzy theory to consider uncertainties in experts' judgments.

The proposed approach consist of three stages: the first stage of hybrid model used fuzzy FMEA method to identify the failure mode risks and derive the RPN values. The second stage applied Fuzzy Decision-Making Trial and Evaluation Laboratory (FDEMATEL) method to determine the interdependencies between the FMs which are defined through fuzzy FMEA. Then, analytic network process (ANP) is applied in the third stage to calculate the weights of FMs based on the interdependencies that are generated through FDEMATEL method. Finally, weight of FMs through fuzzy FMEA and FDEMATEL–ANP are multiplied to generate the final weights for prioritization. Afterward, a case study for a commercial building project is introduced to illustrate proficiency of model.

The results showed that the suggested approach could reveal the important FMs and specify the interdependencies between them successfully. Overall, the suggested model can be considered as an efficient hybrid FMEA approach for risk prioritization.

The originality of approach comes from its ability to consider interdependencies between FMs and uncertainties of experts' judgments.

For years, traditional techniques have been used for diabetes treatment. There are two major types of insulin: insulin analogs and regular insulin. Insulin analogs are similar to regular insulin and lead to changes in pharmacokinetic and pharmacodynamic properties. The purpose of the present research was to determine the cost-effectiveness of insulin analogs versus regular insulin for diabetes control in Yazd Diabetes Center in 2017.

In this descriptive–analytical research, the cost-effectiveness index was used to compare insulin analogs and regular insulin (pen/vial) for treatment of diabetes. Data were analyzed in the TreeAge Software and a decision tree was constructed. A 10% discount rate was used for ICER sensitivity analysis. Cost-effectiveness was examined from a provider's perspective.

QALY was calculated to be 0.2 for diabetic patients using insulin analogs and 0.05 for those using regular insulin. The average cost was $3.228 for analog users and $1.826 for regular insulin users. An ICER of $0.093506/QALY was obtained. The present findings suggest that insulin analogs are more cost-effective than regular insulin.

This study was conducted using a cost-effectiveness analysis to evaluate insulin analogs versus regular insulin in controlling diabetes. The results of study are helpful to the government to allocate more resources to apply the cost-effective method of the treatment and to protect patients with diabetes from the high cost of treatment.