Isolated centrifugal fans are widely utilized in air conditioning system and their performance is closely related to the energy consumption of the system. The purpose of this work is to enlarge the fan operation range without reducing peak efficiency. An improved class and shape function method coupled the Kriging model is proposed to design fan airfoils and to optimize the efficiency and static pressure of the fan. Numerical simulation and experimental study show that both pressure coefficients in large and small flow rate are improved by this optimized fan, and the peak efficiency remains to be unchanged almost under design condition. Optimized pressure coefficient increased by 2.17% in design condition. Furthermore, operation range of the isolated centrifugal fan is enlarged via optimization design scheme and Surrogate model. A better understanding of the physical mechanisms involved isolated centrifugal fan is further investigated.

Energy harvesting is a conventional method to collect the dissipated energy of a system. In this paper, we investigate the optimal location of a piezoelectric element to harvest maximum power concerning different excitation frequencies of a vibrating cantilever beam. The cantilever beam oscillates by a concentrated sinusoidal tip force, and a piezoelectric patch is integrated on the beam to generate electrical energy. To this end, the system is modeled with analytical governing equations, then a Deep Neural Network (DNN)-based Surrogate model is developed to appropriately model the system within the range of its first three natural frequencies. The Surrogate model has significantly abated the computation cost. Thus, the optimization time is reduced drastically. Our investigations led to an optimal piezoelectric location for different excitation frequencies, which can result in maximum electrical output power. This location is highly dependent on the excitation frequency. When excitation frequency equals to natural frequencies, the maximum harvested power increases considerably.

Conceptual design optimization of spacecraft systems is a complex and multidisciplinary process. In this case evaluation of the objective functions relies heavily on running iterative simulation models and analysis codes between various subsystems (such as structures, payload, electrical power supply, attitude determination and control, communication, command and data handling). The conventional sequential optimization approaches to such a complex design problem is time consuming and does not guarantee to achieve the best compromise among the various competing coupled subsystems, and may even lead to non-optimal design. In addition, the design search space can be multi-modal, non-convex with multiple local minima and hence it is time consuming or difficult to rapidly evaluate trade-offs between various subsystems (disciplines). To address these issues, in this paper an efficient Surrogate (response surface) model-based multidisciplinary spacecraft systems design optimization technique with discrete and continuous design variables is presented. The methodology is based on the utilization of genetic algorithms (GA) for both system level and discipline level as an optimizer. Surrogate-modeling as an efficient tool is also used to decrease computational cost in discipline (subsystem) level within a collaborative optimization (CO) framework. Results obtained in this study show that the method introduced in this paper provides an effective way of improving computational efficiency of a complex space system design such as conceptual design optimization of a spacecraft.

This paper introduces a variant version of the AO for efficiently solving high-dimensional computationally expensive problems. Traditional optimization techniques struggle with problems characterized by expensive objective functions and a large number of variables. To address this challenge, this paper proposes a SMAO that leverages machine learning techniques to approximate the objective function. SMAO utilizes RBF to build an accurate and efficient Surrogate model. By iteratively optimizing the Surrogate model, the search process is directed toward the global optimum while significantly reducing the computational cost compared to traditional optimization methods. To evaluate and compare the performance of SMAO with the Surrogate model-based versions of the Gazelle Optimization Algorithm GOA, RSA, PDO, and FLA, they are analyzed on a set of benchmark test functions with dimensions varying from 30 to 200. According to the reported results, SMAO has a higher performance compared to others in terms of achieving the nearest solutions to an optimum, early convergence, and accuracy.

In the present paper, from the results of an approximation method named structural index that was used as the first step, the process of design and optimization of stiffened panel with Gaussian type Surrogate model are carried out. modeling phase is based on the finite element analyses of the structure. Nonlinear buckling load is set as the design constraint. The Surrogate model is employed to reduce the number of finite element analyses in the optimization process. Therefore time of design process is reduced. Using infill points in the modeling and optimization process, convergence to local optima is ensured. Introducing a novel technique, finding the global optimum of the Surrogate model is guaranteed. The approach of Surrogate based optimization is illustrated using two test problems. Also, the sensitivity of the response to the initial sampling plan is investigated. Convergence criteria usually used in Surrogate based optimization is modified to speed the convergence but does not affect the quality of the response. Design optimization process is presented for two types of stiffened panels. In type 1 stiffened panel with 4 design variables, the initial training set is constructed using 55 points. The response is obtained after addition of 5 infill points. For type 2, the initial sampling plan is selected to be 58 points. The optimization process is stopped after adding 173 infill points. Finally, obtained results are compared with the results of structural index method and an approach toward global optimum of the compression stiffened panel is introduced with the characteristics of optimum structure.

Objective: Surrogate motherhood represents one of the most controversial forms of commercialization in reproduction Since it was first applied twenty-three years ago in Great Britain, it has been a subject of numerous ethical, medical and legal discussions, and its outcomes have often had epilogues in long-lasting court proceedings.Materials and Methods: Consideration of Surrogate motherhood in light of numerous ethical dilemmas that this form of reproduction brings.Results: In the case of commercial Surrogate motherhood there are analysts who are in favor, and those who are explicitly against this method of producing offspring. Thus the advocates of Surrogate motherhood believe it is acceptable in case it does not cause harm to any other being, and also that every female person has the right to have children, even through Surrogate motherhood, if that will make her happy, and therefore Surrogate motherhood should be allowed in the whole world. Opposed to this are the viewpoints that Surrogate motherhood is not ethical, as it represents parenthood for profit, exploits women of weaker material status, reduces women’s honor. From the ethical point of view, there are additional imposing questions, such as: what should be done if a Surrogate mother decides to keep the child? What if she wants to visit the child? Is giving a baby over after delivery actually a classical sale? Is renting of Surrogate mothers moral and under which conditions, and what kind of women could be Surrogate mothers? If we assume that Surrogate motherhood is actually legally permitted, a question is raised whether that would result in certain women simply deciding to, out of pure convenience, produce all their children in a way that their child is carried by another person. Considering that in most cases it is the women of lower economic class who apply to be Surrogate mothers, such contracts could perhaps lead to another division between the rich and the poor. A separate issue is the morality of a Surrogate mother and her approach to pregnancy in relation to her previous way of life. On the other hand, the necessary ethical approach of contractors – customers of a Surrogate mother is not negligible in cases when she gives birth to a disabled or malformed child, or becomes ill during pregnancy, and suffers death in pregnancy or at labour.Conclusion: A desire for motherhood is one of fundamental aspirations that accompany the mankind through centuries. One of the ways to realize it in the last decades has also been the commercial Surrogate motherhood. Still, it is prohibited in a large number of countries as an unethical method of trade in human life, together with the opinion that it represents exploitation of women and their organs. However, the justification of such a solution needs to be considered in couples that due to objective reasons have Surrogate motherhood as the only option. Considering a series of not only ethical, but also medical, legal and social controversies that accompany commercial Surrogate motherhood, it should be strictly limited by a reaction of the criminal law. That would prevent manipulations, and a possibility for such contracts to result in long-lasting court proceedings that will impair the quality of life of not only the contractors and the Surrogate mother, but also of the child born this way.