scholarly journals Robust optimization for composite blade of wind turbine based on kriging model

2020 ◽  
Vol 29 ◽  
pp. 2633366X2091463
Author(s):  
Yuqiao Zheng ◽  
Huidong Ma ◽  
Jianfeng Wei ◽  
Kai Zhu
Keyword(s):  
Robust Optimization ◽  
Natural Frequency ◽  
Kriging Model ◽  
The Other ◽  
Optimization Models ◽  
Approximation Model ◽  
Objective Functions ◽  
Composite Blade ◽  
First Case ◽  
Kriging Approximation

Structural optimization models often feature many uncertain factors, which can be handled by robust optimization. This work presents a complete robust optimization program for composite blade based on the kriging approximation model. Two case studies were given and performed using a genetic algorithm. The first being typical optimization, where the first natural frequency of the blade is selected as the optimized objective and the optimal sizing distribution for the entire blade shell is sought to ignore the uncertain factors. The other case determines the standard deviation of the optimized objective in the first case as another optimization goal. Moreover, a 6 σ robustness for the optimization results of the two cases was evaluated. The result shows that typical optimization increases the first natural frequency of the blade by 19%, while its robustness level has a reduction of 61% compared with the first blade. Nevertheless, the robust optimization not only results in an increment of 15.4% in the first natural frequency of the blade but also increases its robustness level by up to 90%. Therefore, the proposed approach can effectively improve optimization objectives, especially reduce the impacts of uncertainties on the objective functions.

A robust structural design method using the Kriging model to define the probability of design success

2010 ◽  
Vol 224 (2) ◽  
pp. 379-388 ◽  
Author(s):  
K-H Lee
Keyword(s):  
Robust Optimization ◽  
Design Method ◽  
Mathematical Problem ◽  
Kriging Model ◽  
Optimization Method ◽  
Design Problems ◽  
Kriging Metamodel ◽  
Mean And Variance ◽  
Kriging Approximation ◽  
Design Requirements

In this study, a robust optimization method is proposed by introducing the Kriging approximation model and defining the probability of design-success. A key problem in robust optimization is that the mean and the variation of a response cannot be calculated easily. This research presents an implementation of the approximate statistical moment method based on the Kriging metamodel. Furthermore, the statistics using the second-order statistical approximation method are adopted to avoid the local robust optimum. Thus, the probability of design-success, which is defined as the probability of satisfying the imposed design requirements, is represented as a function of approximate mean and variance. The formulation for the robust optimization can be defined as the probability of design-success of each response. The mathematical problem and the design problems of a two-bar structure and microgyroscope are investigated for the validation of the proposed method.

Multi-Objective Optimization of Pin-Fin Heatsinks

2009 ◽  
Author(s):  
Keisuke Horiuchi ◽  
Atsuo Nishihara ◽  
Kazuyuki Sugimura
Keyword(s):  
Pressure Drop ◽  
Thermal Resistance ◽  
Approximation Model ◽  
Objective Functions ◽  
Multi Objective Optimization ◽  
Pareto Solutions ◽  
Multi Objective ◽  
Pin Fin ◽  
Design Variables ◽  
Kriging Approximation

The multi-objective optimization of pin-fin heatsinks using a Kriging approximation model is presented based on systematic experimental results. Thermal resistance and pressure drop are the objective functions in this study. Pareto solutions to the objective functions are illustrated. We derived the design rules for the diameter, height, and pitches for the uniform staggered arrays of pin-fin heatsinks by correlating the objective functions with design variables. We also analyzed the contribution of all design variables to the thermal resistance as well as the pressure drop. We found that both the thermal resistance and the pressure drop are the most sensitive to the ratio of transverse pitch to pin-fin diameter.

A NEW APPROACH TO THE STUDY OF COORDINATIVE CONSTRUCTIONS

2019 ◽  
pp. 175-187
Author(s):  
Anna Varnayeva
Keyword(s):  
Characteristic Property ◽  
Mathematical Concept ◽  
The Other ◽  
New Approach ◽  
Logical Aspect ◽  
First Case

Coordinative constructions are traditionally opposed to subordinative constructions. However, this opposition comes down to denial of dependence in coordinative constructions. Thereby the parity of these two constructions does not come to light: subordinative construction can be described without coordinative one. This situation is not improved by detection of a coordinative triangle in all coordinative constructions. The article shows a new approach in the study of coordinative constructions: a coordinative construction is a system; there are not only specific relations – a coordinative triangle, – but also specific elements. Novelty of the study consists in the address to extralinguistic facts, viz. a mathematical concept of a set and its elements. There are a lot of similarities between them. A set in mathematics includes generalizing elements and the composed row in coordinative constructions; in the first case the set is not partitioned, in the second case it is partitioned. In mathematics equivalent components in coordinative constructions correspond to the set elements. A characteristic property in mathematics is homogeneity in coordinative constructions and etc. It is firstly demonstrated, that coordinative and subordinative constructions are correlative and the study of one construction is impossible without the study of the other one. Their parity is shown in coordinative constructions with elements of one set, in subordinative ones with elements of different sets. Cf.: roses and tulips –red roses. In the coordinatiму construction elements of one set are called: «flowers »; in the subordinative construction there are elements of different sets: «flowers » and «colors». It should be noted that the mathematical concept of a set relates to so called logical aspect in linguistics or thinking about reality.

scholarly journals Intramax and other objective functions: The case of Slovenia

2016 ◽  
Vol 24 (2) ◽  
pp. 12-25 ◽  
Author(s):  
Samo Drobne ◽  
Mitja Lakner
Keyword(s):  
Objective Function ◽  
The Other ◽  
Objective Functions ◽  
Interaction Index ◽  
Functional Regions ◽  
Hierarchical Aggregation ◽  
Administrative Units

Abstract The use of different objective functions in hierarchical aggregation procedures is examined in this paper. Specifically, we analyse the use of the original Intramax objective function, the sum-of-flows objective function, the sum-of-proportions-to-intra-regional-flows objective function, Smart’s weighted interaction index, the first and second CURDS weighted interaction indices, and Tolbert and Killian’s interaction index. The results of the functional regionalisation have been evaluated by self-containment statistics, and they show that the use of the original Intramax procedure tends to delineate operationally the most persuasive and balanced regions that, regarding the intra-regional flows, homogeneously cover the analysed territory. The other objective functions give statistically better but operationally less suitable results. Functional regions modelled using the original Intramax procedure were compared to the regions at NUTS 2 and NUTS 3 levels, as well as to administrative units in Slovenia. We conclude that there are some promising directions for further research on functional regionalisation using hierarchical aggregation procedures.

BRAIN TUMORS IN INFANCY

PEDIATRICS ◽  
1948 ◽  
Vol 1 (3) ◽  
pp. 346-363
Author(s):  
I. WALLACE LEIBNER
Keyword(s):  
Nervous System ◽  
Differential Diagnosis ◽  
Brain Tumors ◽  
Correct Diagnosis ◽  
Full Recovery ◽  
The Other ◽  
Congenital Hydrocephalus ◽  
First Case ◽  
Clinical Patterns

Seven cases of brain tumors occurring in infants are presented. Six occurred in males and one was in a female. Three of them arose in the cerebellum while the other four were supratentorial. The tumors included two medulloblastomas, one [See Table II in Source Pdf] spongioblastoma polare, one ependymoma, one astrocytoma and one hemangioblastoma. The seventh case probably was also one of medulloblastoma. One of the proven medulloblastomas was supratentorial, which is unusual so faras location is concerned. The hemangioblastoma arose in the cerebrum. The location of this tumor is also a rare one and to my knowledge, it is the first case of its type reported in an infant in whom full recovery occurred following removal of the tumor. The diagnosis was unsuspected in four cases. Three of these infants were believed to be suffering from congenital hydrocephalus while the fourth was thought to be afflicted with encephalitis. The ways in which the correct diagnosis might have been made are discussed. Since bizarre clinical patterns are sometimes produced by brain tumors in infants and the diagnosis frequently overlooked, the possibility should be kept in mind by the pediatrician in considering the differential diagnosis of conditions producing signs referable to the nervous system.

Significance of analysis of the mechanism of fingermarks formation, sizes and location – casework examples

2018 ◽  
Vol 301 ◽  
pp. 44-52
Author(s):  
Tomasz Kowalski ◽  
Keyword(s):  
Significant Role ◽  
Special Interest ◽  
The Other ◽  
Fatal Accident ◽  
Preliminary Stage ◽  
Additional Information ◽  
Expert Opinions ◽  
First Case ◽  
Initial Stage

The aim of the article to present the role of analysing the manner of generating fingermarks in the investigative proceedings. These examinations are based on the analysis of the location of the marks on a given background and aim at providing the requesting party additional information about the circumstances of the investigated incident. The Author refers to two unusual cases, in which Voivodeship Police Command Forensic Laboratory issued expert opinions in the area of fingerprint identification. In the first case, at the initial stage of the proceedings the circumstances and recovered evidential fingermarks indicated a fatal accident or manslaughter by means of a firearm. In the other case at the preliminary stage recovered evidence did not allow identification of the perpetrator due to incorrectly selected exhibits. These cases would not be off special interest to us without the significant role of proper recovering of fingermarks and their analysis in a broader context than just identification.

Pseudo-Restitutionary Damages: Some Thoughts on the Dual Theory of Restitution for Wrongs

2009 ◽  
Vol 22 (1) ◽  
pp. 49-78 ◽  
Author(s):  
Francesco Giglio
Keyword(s):  
The Other ◽  
Corrective Justice ◽  
Dual Theory ◽  
Judicial Decision ◽  
Legal Response ◽  
First Case ◽  
The Law ◽  
Compensatory Damages ◽  
Single Response

Restitution for civil wrongs, also known as restitutionary damages, is a legal response through which the defendant’s wrongful gain is awarded to the claimant. James Edelman has recently advocated two different restitutionary responses for wrongs. One response, termed ‘restitutionary damages’, would aim to compel the wrongdoer to give back to the victim a wrongful gain, whereas the other response, ‘disgorgement damages’, would oblige the wrongdoer to give up a wrongful gain for the benefit of the claimant.In the first case, the claimant would obtain what should have never left his assets. In the second case, the claimant would be the beneficiary of a judicial decision according to which a wrongful gain should not be kept by the wrongdoer. In this essay, I seek to demonstrate that this taxonomy cannot be accepted. I argue that Edelman’s ‘disgorgement damages’ are the only true example of restitution for wrongs, whereas his ’restitutionary damages’ are simply compensatory damages which are quantified in a particular fashion. Edelman’s ‘restitutionary damages’ might appear to deprive the defendant of his gain, and thus to achieve a restitutionary goal. Yet they nullify the victim’s loss and therefore have a compensatory nature. They are ‘pseudo-restitutionary damages’. In opposition to the dual theory, I submit a model of restitutionary damages based upon a single response which is coherent with the tenets of corrective justice. Given that it deals mainly with Edelman’s ‘restitutionary damages’, this article is not so much about restitution for wrongs but rather about compensation, which is what Edelman’s ‘restitutionary damages’ really concerns. The theory which I propose, based upon a single restitutionary response for wrongs, solves the taxonomic incoherence of Edelman’s dual theory. It also reflects the law as we find it, being supportable by reference to the available judicial authorities.

Placement of endovascular stents for systemic venous obstruction after the Mustard operation

1994 ◽  
Vol 4 (4) ◽  
pp. 390-394 ◽  
Author(s):  
Jassim M. Abdulhamed ◽  
Saad Al Yousef ◽  
Mohamed A. Ali Khan ◽  
Martin O'Laughlin
Keyword(s):  
Balloon Catheter ◽  
Balloon Dilation ◽  
The Other ◽  
Complete Relief ◽  
Venous Obstruction ◽  
Endovascular Stents ◽  
The Third ◽  
Mustard Operation ◽  
First Case ◽  
Stenotic Area

AbstractThree patients aged five years, five years four months and 14 years with obstruction of the systemic venous baffle following the Mustard operation were treated with balloon dilation and implantation ofstents. Balloon dilation of the baffle obstruction was performed initially in the first two cases. In the third case, the obstruction was complete and was punctured with atranseptal needle via a 6 French transeptal sheath followed by a balloon dilation. in all three patients, a Palmaz stent (Johnson & Johnson, Summerville, New Jersey, USA) was loaded onto the balloon catheter and delivered into the stenotic area. There was complete relief of obstruction in allcases. The first case developed supraventricular tachycardia at the time ofcatheterization, the morning following implantation of the stent and thentwo weeks after that. There were no complications with catheterization and noshort-term side effects in the other cases. These cases illustrate the use of endovascular stents in the treatment of baffle obstruction.

A Strategy for Multi-Point Compressor Blading Using Multi-Objective Optimization

2012 ◽  
Author(s):  
Alireza Fathi ◽  
Abdollah Shadaram ◽  
Mohammad Alizadeh
Keyword(s):  
Incidence Angle ◽  
Optimization Algorithms ◽  
Optimization Techniques ◽  
Design System ◽  
Design Calculation ◽  
Blade Design ◽  
Objective Functions ◽  
Multi Objective ◽  
First Case ◽  
Through Flow

This paper introduces a framework to perform a multi-objective multipoint aerodynamic optimization for an axial compressor blade. This framework considers through-flow design requirements and mechanical and manufacturing constraints. Typically, components of a blade design system include geometry generation tools, optimization algorithms, flow solvers, and objective functions. In particular, optimization algorithms and objective functions are tuned to reduce blade design calculation cost and to match designed blade performance to the through flow design criteria and mechanical and manufacturing constrains. In the present study, geometry parameters of blade are classified to three categories. For each category, a distinct optimization loop is applied. In outer loop, Gradient-based optimization techniques are used to optimize parameters of the second category and a two-dimensional compressible viscous flow code is used to simulate the cascade fluid flow. Surface curvature optimization is carried out in inner loop, and its objective function is defined by integrating the normalized curvature and curvature slope. The genetic algorithm is used to optimize the parameters in the interior loop. To highlight the capabilities of the design method and to develop design know-how, an initial profile is optimized with three different design philosophies. The highest performance improvement in the first case is 15% reduction in loss at design incidence angle. In the second case, 16.5% increase in allowable incidence angle range, improves blade’s performance at off design conditions.

scholarly journals An evolutionary-based optimization algorithm for truss sizing design

2016 ◽  
Vol 38 (4) ◽  
pp. 307-317
Author(s):  
Pham Hoang Anh
Keyword(s):  
Local Search ◽  
Objective Function ◽  
Optimization Algorithm ◽  
Optimization Problems ◽  
Optimal Solution ◽  
The Other ◽  
Truss Structures ◽  
Benchmark Problems ◽  
Discrete Variables ◽  
Objective Functions

In this paper, the optimal sizing of truss structures is solved using a novel evolutionary-based optimization algorithm. The efficiency of the proposed method lies in the combination of global search and local search, in which the global move is applied for a set of random solutions whereas the local move is performed on the other solutions in the search population. Three truss sizing benchmark problems with discrete variables are used to examine the performance of the proposed algorithm. Objective functions of the optimization problems are minimum weights of the whole truss structures and constraints are stress in members and displacement at nodes. Here, the constraints and objective function are treated separately so that both function and constraint evaluations can be saved. The results show that the new algorithm can find optimal solution effectively and it is competitive with some recent metaheuristic algorithms in terms of number of structural analyses required.

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