Visual Attention Software: A New Tool for Understanding the “Subliminal” Experience of the Built Environment

Eye-tracking technology is a biometric tool that has found many commercial and research applications. The recent advent of affordable wearable sensors has considerably expanded the range of these possibilities to fields such as computer gaming, education, entertainment, health, neuromarketing, psychology, etc. The Visual Attention Software by 3M (3M-VAS) is an artificial intelligence application that was formulated using experimental data from eye-tracking. It can be used to predict viewer reactions to images, generating fixation point probability maps and fixation point sequence estimations, thus revealing pre-attentive processing of visual stimuli with a very high degree of accuracy. We have used 3M-VAS software in an innovative implementation to analyze images of different buildings, either in their original state or photographically manipulated, as well as various geometric patterns. The software not only reveals non-obvious fixation points, but also overall relative design coherence, a key element of Christopher Alexander’s theory of geometrical order. A more evenly distributed field of attention seen in some structures contrasts with other buildings being ignored, those showing instead unconnected points of splintered attention. Our findings are non-intuitive and surprising. We link these results to both Alexander’s theory and Neuroscience, identify potential pitfalls in the software’s use, and also suggest ways to avoid them.

Finding the Optimal Size of Permanent Magnets for a Transverse Magnetic Flux Generator with a Disk Rotor

Based on the analysis of the transverse flux machine designs, they were found to have a relative design simplicity and a high-power density. The purpose of this work is to determine the optimal height of a permanent magnet and to define its effect on the induced EMF value in the stator coils and the cogging torque, as well as to define the picture of the magnetic flux leakage between the stator poles. To achieve these goals, the 3D model of a low speed generator was studied. The electromagnetic analysis was carried out using a modern software, which allows us to determine the magnetic field distribution in the 3D, as well as the induced EMF value and the rotor cogging torque. The criterion for the optimal calculation is the highest EMF value at the minimum value of the rotor cogging torque. The parameters of the permanent magnets, such as the width and length, remained unchanged, whereas, the height varied from 1 to 8 mm at a 1-mm step. The corresponding dependencies are obtained for each height. The most significant result of the work is the conclusion that the height of the permanent magnet should not exceed the 3-mm value. The significance of the obtained results is that the used methodology allowed finding the optimal height of the permanent magnet, since a further increase in its height leads to no growth in the EMF value, but rather significantly enhances the negative effect from the rotor cogging torque. In addition, the simulation results were supported experimentally.

Study on Model-Based Systems Engineering Method for Modeling of Thermal Power System

Thermal power systems, particularly with large capacity and high operating parameters, are more and more complicated nowadays, which include machinery, electronics, electrical, hydraulic, thermal, control, and process-oriented subsystems. The traditional development method based on documents has the problems of difficulty to reuse the designed elements, weak traceability of requirements, and lack of top-level logic verification. Moreover, there is a large gap because different models, tools and terminology are used during design process. The gap results in inefficiencies and quality issues that can be very expensive. In this paper, a model-based systems engineering (MBSE) approach is introduced for the top-down design flow of thermal power systems. The MBSE method can perfected the requirement definition, complete the mapping of the requirements to the system elements, realize the function logic verification, and support requirements verification at all stages. A GOPPRR (graph, object, point, property, role, relationship) meta-modeling method is proposed to support the MBSE formalisms. An Architecture Analysis and Design Integrated Approach (Arcadia) framework is adopted to capture the complex architecture, which is a standardized modeling method including requirement analysis, function analysis, logic analysis, and architecture design. Based on the architecture-driven algorithm and code generation, the standardized modeling process can establish a traceable relationship at each design stage and can verify the availability of initial requirements. Moreover, the designed elements of previous work can be reused in other relative design processes. The proposed MBSE method in this paper is applied to establish a gas turbine performance simulation model. The entire modeling process is enhanced by managing the relative design information consistently. The performance of the design process with MBSE method is analyzed and compared from different aspects. The results show that the performance simulation model of the power system established by the MBSE method can effectively describe the requirements, functions, logic, and architecture during design process. Based on the MBSE method, the requirements of the system are refined, traced and verified.

Implementación de Motor Stirling para generación de energía eléctrica limpia empleando una lente de Fresnel

In search of expanding the generation of electric power and reduce the burning of fossil fuels. It is proposed to use the tools that already have and the necessary information to make a prototype of Alfa type Stirling engine, which is a thermal machine with low levels of noise and toxic emissions, that its relative design is of low manufacturing cost for the generation of clean electrical energy, for the heating we will use a Fresnel lens with the purpose of satisfying the thermal energy demand of the same, in the sense of achieving the best angle of capture of solar rays, at the same time achieving the highest concentration of heat possible for the heating angle of the motor. The validation of the proposed model is based on experimental results, using the information obtained from the production of electrical energy, with this the validation of the prototype will be performed, similar to the solar parabolic dish concentrator.

Expedited antenna optimization with numerical derivatives and gradient change tracking

Purpose The purpose of this study is to propose a framework for expedited antenna optimization with numerical derivatives involving gradient variation monitoring throughout the optimization run and demonstrate it using a benchmark set of real-world wideband antennas. A comprehensive analysis of the algorithm performance involving multiple starting points is provided. The optimization results are compared with a conventional trust-region (TR) procedure, as well as the state-of-the-art accelerated TR algorithms. Design/methodology/approach The proposed algorithm is a modification of the TR gradient-based algorithm with numerical derivatives in which a monitoring of changes of the system response gradients is performed throughout the algorithm run. The gradient variations between consecutive iterations are quantified by an appropriately developed metric. Upon detecting stable patterns for particular parameter sensitivities, the costly finite differentiation (FD)-based gradient updates are suppressed; hence, the overall number of full-wave electromagnetic (EM) simulations is significantly reduced. This leads to considerable computational savings without compromising the design quality. Findings Monitoring of the antenna response sensitivity variations during the optimization process enables to detect the parameters for which updating the gradient information is not necessary at every iteration. When incorporated into the TR gradient-search procedures, the approach permits reduction of the computational cost of the optimization process. The proposed technique is dedicated to expedite direct optimization of antenna structures, but it can also be applied to speed up surrogate-assisted tasks, especially solving sub-problems that involve performing numerous evaluations of coarse-discretization models. Research limitations/implications The introduced methodology opens up new possibilities for future developments of accelerated antenna optimization procedures. In particular, the presented routine can be combined with the previously reported techniques that involve replacing FD with the Broyden formula for directions that are satisfactorily well aligned with the most recent design relocation and/or performing FD in a sparse manner based on relative design relocation (with respect to the current search region) in consecutive algorithm iterations. Originality/value Benchmarking against a conventional TR procedure, as well as previously reported methods, confirms improved efficiency and reliability of the proposed approach. The applications of the framework include direct EM-driven design closure, along with surrogate-based optimization within variable-fidelity surrogate-assisted procedures. To the best of the authors’ knowledge, no comparable approach to antenna optimization has been reported elsewhere. Particularly, it surmounts established methodology by carrying out constant supervision of the antenna response gradient throughout successive algorithm iterations and using gathered observations to properly guide the optimization routine.

Investigation of Micro Gas Turbine Systems for High Speed Long Loiter Tactical Unmanned Air Systems

In this study, the on-going research into the improvement of micro-gas turbine propulsion system performance and the suitability for its application as propulsion systems for small tactical UAVs (<600 kg) is investigated. The study is focused around the concept of converting existing micro turbojet engines into turbofans with the use of a continuously variable gearbox, thus maintaining a single spool configuration and relative design simplicity. This is an effort to reduce the initial engine development cost, whilst improving the propulsive performance. The BMT 120 KS micro turbojet engine is selected for the performance evaluation of the conversion process using the gas turbine performance software GasTurb13. The preliminary design of a matched low-pressure compressor (LPC) for the proposed engine is then performed using meanline calculation methods. According to the analysis that is carried out, an improvement in the converted micro gas turbine engine performance, in terms of thrust and specific fuel consumption is achieved. Furthermore, with the introduction of a CVT gearbox, the fan speed operation may be adjusted independently of the core, allowing an increased thrust generation or better fuel consumption. This therefore enables a wider gamut of operating conditions and enhances the performance and scope of the tactical UAV.

Investigation of Micro Gas Turbine Systems for High Speed Long Loiter Tactical Unmanned Air Systems

In this study, the on-going research into the improvement of micro-gas turbine propulsion system performance and the suitability for application as propulsion systems for small tactical UAVs (&lt;600 kg) is investigated. The study is focused around the concept of converting existing micro turbojet engines to turbofan with the use of a continuously variable gearbox, thus maintaining a single spool configuration and relative design simplicity. This is an effort to reduce the initial engine development cost, whilst improving propulsive performance. The BMT 120 KS micro turbojet engine is selected for performance evaluation of the conversion process using gas turbine performance software, GasTurb13. The preliminary design of a matched low-pressure compressor (LPC) for the proposed engine is then performed using meanline calculation methods. According to the analysis carried out, an improvement in the converted micro gas turbine engine performance in terms of thrust and specific fuel consumption is achieved. Furthermore, with the introduction of a CVT gearbox, fan speed operation may be adjusted independently of the core, allowing increased thrust generation or better fuel consumption. Therefore, enabling a wider gamut of operating conditions and enhances the performance and scope of tactical UAV.

Design Efficiency Analysis Towards Product Improvement for Eco-Friendly Using DFMA Method

This paper presents the comparative study of design efficiency of two different brands of products, performing the same function using the Design for Manufacturing and Assembly (DFMA) method. The study aims to compare the products on the relative design efficiency. The DFMA method was used as it is a well-established technique for improving the efficiency of the product leading to minimizing production costs. It also shortens product development time by reducing the number of components in a product. The study used two different brands of dry iron as a case study. The result shows that the percentage of the design efficiency of dry iron A is 8.82%, whereas it is 10.34% of dry iron B. Thus, the dry iron B is much better as compared to A in term of its assembly operation and design efficiency. Therefore, the dry iron B is greener than dry iron A. Furthermore, a redesign of dry iron B was proposed and analyzed for the internal validation. The DFMA analysis result shows that the percentage of design efficiency of a new conceptual design of dry iron B increased to 18.08%. The application of the DFMA method to enhance the eco-friendliness of a product has been proven to be highly useful in design work.

Shearing Property Study on PC Box-Girder Bridge with Corrugated Webs

PC box-girder bridge with corrugated webs is a new kind of bridge, which named by the thin steel webs replacing thick concrete webs. It is applied abroad in China recently, which attracts attention for its shearing property. Because of lacking relative design and construction code interiorly, the related data of Mi-Luo-Jiang bridge was used in the study with the software ANSYS 10.0. The shearing property and bucking stability of Mi-Luo-Jiang bridge were studied and a theory was verified: corrugated webs do not bear moment and axial force. Besides, the result that the decisive parameter of shearing property of Mi-Luo-Jiang bridge should be allowable shear stress is obtained. The other study had been done on buckling stability of box-girder bridge with different corrugated shapes, maintaining other parameters invariant. Finally, the optimal scope of lateral plane length is [0.2,0.4], and the optimal scope of folded angle is [20º,50º]. The parameters used in Mi-Luo-Jiang bridge is verified as the best value. This study is meaningful and the results can be applied in the design and construction of the same type bridge.