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The entity‐relationship approach is applied to similarity‐driven pictorial database design. The capabilities and the limitations of computers are presented. Advantages of the entity‐relationship approach, and similarity‐driven pictorial database design are also presented. Classification of pictures, similarity‐driven face databases, chromosome databases, leukocyte databases are investigated. Quantitative measure of equal‐perimeter circular shape, equal‐area circular shape, elongated, spiculed, indented, slightly indented, and deeply indented leukocytes are also investigated. The entity‐relationship diagrams of a house, a house with high roof, and a church are shown as illustrative examples of this approach. The class of elongated isosceles triangles is viewed as a “fuzzy entity”. Topics for future research are also stated. The results have useful applications in data engineering, knowledge engineering, pattern recognition, artificial intelligence, fuzzy language theory, computer graphics, expert systems and pictorial database design.

The purpose of this paper is to investigate the performance of Passive Direct Methanol Fuel Cell (PDMFC) experimentally using various Membrane Electrode Assembly (MEA) shapes such as square, rectangle, rhombus, and circle with equal areas and equal perimeters. The variation in MEA shape/size is achieved by altering gasket openings in the dynamic regions.

In the equal areas of MEA shapes, gasket opening areas of 1963.5 (+/−0.2) mm2 are used. Whereas in the equal perimeters of shapes, gasket opening perimeters of 157.1 (+/−0.2) mm are used. In this experimentation, Nickel-201 current collectors with 45.3% of circular openings are used on both the anode and cathode sides. The experiment is carried out at a 5 molar methanol concentration to find out the highest power density of the cell.

In the equal areas, among the shapes that are chosen for investigation, the square shape opening consisting of a perimeter of 177.2 mm has developed a maximum power density of 6.344 mWcm⁻² and a maximum current density of 65.2 mAcm⁻². Similarly, in equal perimeters, the rhombus shape opening with an area of 1400 mm2 has developed a maximum power density of 7.714 mWcm⁻² and a maximum current density of 85.3 mAcm⁻².

The novelty of this research work is instead of fabricating various shapes and sizes of highly expensive MEAs, the desired shapes and sizes of the MEA are achieved by altering gasket openings over dynamic regions to find out the highest power density of the cell.

The concept of a fuzzy language is applied to pattern recognition using geometric figures, chromosomes and leukocytes as illustrative examples. For chromosomes, an algorithm for classifying a chromosome image as an “approximate median chromosome,” “approximate sub‐median chromosome” or “approximate acrocentric chromosome” is presented. For leukocytes, an equal‐perimeter circular shape measure and an equal‐area circular shape measure are proposed, and various properties, results, and the relationship between these two measures are presented. Quantitative measures of other visual concepts such as elongated, spiculed, indented, slightly indented and deeply indented arc also presented and illustrated by examples. The results obtained in this paper may have useful applications in pattern recognition, cybernetics and fuzzy systems.

The structural design problem can be viewed as an iterative design loop with each iteration involving two stages for topology and shape designs with genetic algorithm (GA) as the optimization tool for both.

The topology optimization problem, which is ill posed, is regularized using a constraint on perimeter and solved using GA. The problem is formulated as one of compliance minimization subject to volume constraint for the single loading case. A dual formulation of this has been used for the multiple loading cases resulting in as many behavioral constraints as there are loading cases. The tentative topology given by the topology optimization module is taken and the domain boundary is approximated using straight lines, B‐splines and cubic spline curves and design variables are selected among the boundary defining points. Optimum boundary shape of the problem has been obtained using GA in two different ways: without stress constraints; and with stress constraints.

The proposed two stage strategy has been tested on benchmark structural optimization problems and its performance is found to be extremely good.

The strategy appears to be eminently suitable for implementation in a general purpose FE software as an add‐on module for structural design optimization.

It has been observed that the integrated topology and shape design method is robust and easy to implement in comparison with other techniques. The computing time requirements for the GA does not appear daunting in the present scenario of high performance parallel computing and improved GA techniques.

This study aims to investigate numerically the problem of conjugate conduction and mixed convection heat transfer of a nanofluid in a rotational/stationary circular enclosure using a two-phase mixture model.

Hot and cold surfaces on the wall or inside the enclosure (heater and cooler) are maintained at constant temperature of T_h and T_c, respectively, whereas other parts are thermally insulated. To examine the effects of various parameters such as Richardson number (0.01 = Ri =100), thermal conductivity ratio of solid to base fluid (1 = K_r = 100), volume fraction of nanoparticle (0 = φ = 0.05), insertion of conductive covers (C.Cs) around the heater in a different shape (triangular, circular or square), segmentation and arrangement of the conductive blocks (C.Bs) and rotation direction of the enclosure on the flow structure and heat transfer rate, two-dimensional equations of mass, momentum and energy conservation, as well as volume fraction, are solved using finite volume method and Semi-Implicit Method for Pressure Linked Equations (SIMPLE) algorithm.

The results show that inserting C.C around heater can increase or decrease heat transfer rate, and it depends on thermal conductivity ratio of solid to pure fluid. Also, it is found that by the division of C.B and location of its portions in a horizontal configuration, heat transfer rate reduces. Moreover, it is observed that external heating and cooling of the enclosure causes enhancement of heat transfer relative to that of internal heating and cooling. Finally, results illustrate that under the condition that cylinders rotate in the same direction, the heat transfer rate increases as compared to those that rotate in the opposite direction. Hence rotation direction of cylinders can be used as a desired parameter for controlling heat transfer rate.

A comprehensive report of results for the problem of conjugate conduction and mixed convection heat transfer in a circular cylinder containing different shapes of C.C, conducting obstacle and heater and cooler has been presented. An efficient numerical technique has been developed to solve this problem. The achievements of this paper are purely original, and the numerical results were never published by any researcher.

In this article the author discusses the suitability of existing materials for aircraft structures and shows that a hypothetical material derived by expanding an aluminium alloy would greatly simplify the structure of fuselages

The purpose of this paper is to devise an analytical approach to calculate conductor winding losses, considering multiple contributing aspects simultaneously. These include the geometric configuration of coil windings, frequency of the electric current and the dependency on the coil temperature, derived studying a coupled fluid–solid model considering the cooling system characteristics. The obtained results allow identifying power loss trends according to such system variables as coolant inlet temperature or overall flow rate of the motor.

An easy-to-use coupled analytical approach is applied, which is suitable for rapid estimations of the impact of parameter variation on the resulting conductor winding power losses that facilitates decision-making in the design process of electric aircraft engines.

In the considered cooling parameters, the overall conductor winding power losses vary approximately between 6 kW and 7.2 kW. More than 95 per cent of this loss is because of direct current losses. These losses cause the variation in maximal coil temperature ranging between 115°C and 170°C.

The SP260D motor is set and was currently tested in Extra 330. It recently broke two world records.

One of the current trends in aircraft engineering is electric aircraft. Advantages of electric aircraft include improved manoeuvrability because of greater torque from electric motors, increased safety because of decreased chance of mechanical failure, less risk of explosion or fire in the event of a collision and less noise. There will be environmental and cost benefits associated with the elimination of dependency on fossil fuels and resultant emissions.

The use of a novel fluid–solid interaction model for predicting conductor winding power loss of the SP260D electric aircraft motor has not been done earlier. A novel alternative derivation of the widely applied Dowell’s formula (Dowell, 1966) is presented for the estimation of proximity losses in square winding conductors.

The purpose of this paper is to present a new outsourcing model for materials management related to the operating theatre of hospitals. Two distinguishing features characterize the model: the long-term collaborative network established among the supplying companies (the “Network factor”), and the implementation of the RFID technology along the supply chain (the “RFID factor”). The network factor allows sharing transportation costs, while the RFID factor allows implementing a continuous review policy, instead of the periodic review policy normally utilized in hospitals. In the paper the effect of these two factors on the minimization of total materials management costs is investigated.

An analytical model, validated through a simulation study, is proposed to calculate total management costs of materials, depending on the presence of the network and the RFID factors. Throughout the model it is possible to perform a scenario analysis and individuate the inventory management policy that allows minimizing total costs. The procedure has been applied to a real case study of a long-term collaborative network of supplying companies in the healthcare sector that operates in Central Italy.

The optimal inventory management policy strongly depends on the mutual distances of supplying companies and the hospital. Both of the two factors have an impact on the reduction of total annual costs. The analysis of the scenario shows that a positive interaction effect exists between the two factors, so that higher savings are obtained when both factors are present.

The outsourcing model presented in the paper is new, and the managerial insights that can be drawn from the application of the model to the healthcare sector can be extended to many other industries.

The purpose of this paper is to propose a decision-support methodology for public and private subjects involved in the enhancement of public properties. In particular, with reference to cases in which the disused public property can be sold and the range of functions that define the highest and best use of the conversion was identified, the developed model allows for the assessment of the financial feasibility of the initiatives, in relation to the corresponding investment risks.

The proposed model integrates the mathematical logic of goal programming for the evaluation of the financial conveniences of the parties (public and private) involved in the enhancement of a public property with statistical approaches (value at risk+exponentially weighted moving average) so as to determine the investment risk of the private investor. The application of the model to a real case study highlighted the potentialities of the proposed methodology.

The model allows to determine: the optimal mix of intended uses to be realized in the public property under analysis; the fair value of the public property for the parties involved in the transaction; and the Pareto-optimal frontier of the expected profits, as a function of the risk appetite of the private investor.

The defined model responds to the growing international interest in the enhancement of public buildings, satisfies the objectives of the substantial reduction of soil sealing and urban sustainability, stimulates the urban regeneration of deprived areas of the cities through the reactivation of large buildings that have been disused or underused for too long.

The present research allows to provide effective evaluation tools capable of outlining the opportunities of redevelopment initiatives and examines the risk factors that often invalidate the initial forecasts of the private entrepreneur and/or stop the activation of investments.

The standard diagram is described, giving the relationship between R and S for constant value of N. The line of infinite endurance is obtained, and the relationship of N and S is shown. The effects of stress concentration and of shape are studied and tabulated. The variation of KF with S1 is plotted, and the relationship between KF, KT and S1 is examined. Comments are made on the variation of KF with material, on high compressive stress, on surface finish effect and on the relationship between the grades of light alloy. The effects of bending, riveting and bolting are shown. General discussion summarizes the results and makes suggestions for future research and testing for fatigue. An appendix contains notes on practical use of the results in design, and some examples of fatigue stress analysis and its application to pressurized cabins.