scholarly journals Non-Parametric Shape Optimization of a Football Boot Bottom Plate

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 152
Author(s):  
Jeong-Ro Lee ◽  
Andy Harland ◽  
Jonathan Roberts
Keyword(s):  
Shape Optimization ◽  
Parametric Optimization ◽  
Structure Sensitivity ◽  
Optimization Process ◽  
Optimum Shape ◽  
Bottom Plate ◽  
Future Research ◽  
Key Features ◽  
Non Parametric

This paper describes the non-parametric shape optimization process for a football boot bottom plate. The non-parametric shape optimization process changes the nodes’ location of a model and outputs an optimum shape, which satisfies an optimization objective. The methodology presented in this study was able to change the shape of the football boot bottom plate, especially the dimensions of key features, to achieve four different target bending stiffnesses. Tosca Structure sensitivity-based shape optimization was used to perform the optimization process and output optimum bottom plates. Future research is needed to investigate the accuracy of the process in comparison with that of the previously developed parametric optimization process.

Study of Parametric and Non-Parametric Optimization of a Rotor-Bearing System

2014 ◽  
Author(s):  
Youngwon Hahn ◽  
John I. Cofer
Keyword(s):  
Topology Optimization ◽  
Critical Speed ◽  
Parametric Optimization ◽  
Optimization Methods ◽  
Optimization Process ◽  
Support Structure ◽  
And Topology ◽  
Design Variables ◽  
Rotor Bearing ◽  
Non Parametric

The optimization techniques most widely used in various industrial fields for structural optimization generally can be placed into two categories: parametric optimization and non-parametric optimization. In parametric optimization, the parametric variables defining a geometric model are used as design variables. For example, all dimensions defining a structural shape in a CAD (Computer-Aided Design) system can be used as parameters in an optimization process to achieve a desired objective. In non-parametric optimization, an initial outer boundary of the geometry is defined and the optimization process either removes mass without changing the node locations in the calculation mesh (topology optimization) or directly manipulates the node locations (shape optimization) to achieve a desired objective. Nowadays, the combination of both parametric and non-parametric optimization methods can provide an attractive approach to satisfy the requirements of advanced levels of structural performance. While optimization methods have been widely used in many turbomachinery applications, such as turbine and compressor blading, combustors, and casings, in the rotordynamics field, relatively little work has been done to investigate methods for the overall optimization of rotor-bearing-support structures to achieve desired system behavior. In this paper, a combined parametric and non-parametric optimization method is applied to a rotor-bearing-support structure in order to achieve the desired critical speed and unbalance response. The bearing design variables are selected as parametric design variables and topology optimization is applied to the support structure. The entire optimization workflow is constructed in the commercial software Isight, and Abaqus and ATOM (Abaqus Topology Optimization Module) are used for rotordynamics analysis and topology optimization. The desired critical speed and unbalance response can be obtained with the optimized topology of the support structure.

scholarly journals Mandatory CSR and sustainability reporting: economic analysis and literature review

2021 ◽  
Author(s):  
Hans B. Christensen ◽  
Luzi Hail ◽  
Christian Leuz
Keyword(s):  
Firm Behavior ◽  
Sustainability Reporting ◽  
Economic Effects ◽  
Economic Consequences ◽  
Future Research ◽  
Current Debate ◽  
Reporting Standards ◽  
Csr Reporting ◽  
Key Features ◽  
Corporate Social

AbstractThis study collates potential economic effects of mandated disclosure and reporting standards for corporate social responsibility (CSR) and sustainability topics. We first outline key features of CSR reporting. Next, we draw on relevant academic literatures in accounting, finance, economics, and management to discuss and evaluate the potential economic consequences of a requirement for CSR and sustainability reporting for U.S. firms, including effects in capital markets, on stakeholders other than investors, and on firm behavior. We also discuss issues related to the implementation and enforcement of CSR and sustainability reporting standards as well as two approaches to sustainability reporting that differ in their overarching goals and materiality standards. Our analysis yields a number of insights that are relevant for the current debate on mandatory CSR and sustainability reporting. It also points scholars to avenues for future research.

scholarly journals Build a Better Bootstrap and the RAWR Shall Beat a Random Path to Your Door: Phylogenetic Support Estimation Revisited

2020 ◽  
Author(s):  
Wei Wang ◽  
Kevin J. Liu
Keyword(s):  
State Of The Art ◽  
Bootstrap Method ◽  
Parametric Method ◽  
Open Data ◽  
Bootstrap Support ◽  
Future Research ◽  
Evolutionary Divergence ◽  
Type I ◽  
Support Estimation ◽  
Non Parametric

AbstractMotivationThe standard bootstrap method is used throughout science and engineering to perform general-purpose non-parametric resampling and re-estimation. Among the most widely cited and widely used such applications is the phylogenetic bootstrap method, which Felsenstein proposed in 1985 as a means to place statistical confidence intervals on an estimated phylogeny (or estimate “phylogenetic support”). A key simplifying assumption of the bootstrap method is that input data are independent and identically distributed (i.i.d.). However, the i.i.d. assumption is an over-simplification for biomolecular sequence analysis, as Felsenstein noted. Special-purpose fully parametric or semi-parametric methods for phylogenetic support estimation have since been introduced, some of which are intended to address this concern.ResultsIn this study, we introduce a new sequence-aware non-parametric resampling technique, which we refer to as RAWR (“RAndom Walk Resampling”). RAWR consists of random walks that synthesize and extend the standard bootstrap method and the “mirrored inputs” idea of Landan and Graur. We apply RAWR to the task of phylogenetic support estimation. RAWR’s performance is compared to the state of the art using synthetic and empirical data that span a range of dataset sizes and evolutionary divergence. We show that RAWR support estimates offer comparable or typically superior type I and type II error compared to phylogenetic bootstrap support as well as GUIDANCE2, a state-of-the-art purpose-built fully parametric method. Additional simulation study experiments help to clarify practical considerations regarding RAWR support estimation. We conclude with thoughts on future research directions and the untapped potential for sequence-aware non-parametric resampling and re-estimation.AvailabilityData and software are publicly available under open-source software and open data licenses at: https://gitlab.msu.edu/liulab/[email protected]

scholarly journals Оптимизация алюминиевой крышки люкового закрытия сухогрузного судна

2020 ◽  
Author(s):  
G.B. Kryzhevich ◽  
A.R. Filatov
Keyword(s):  
Shape Optimization ◽  
Parametric Optimization ◽  
Optimization Methods ◽  
Topological Optimization ◽  
Design And Technology ◽  
Bulk Carrier ◽  
Material Consumption ◽  
Considerable Decrease ◽  
Bulk Carriers ◽  
Cargo Transportation

Объектом исследования является крышка люкового закрытия сухогрузного судна, служащая для обеспечения непроницаемости грузовых помещений и перевозки на ней грузов и обеспечивающая безопасность сухогрузных судов и осуществляемой на них морской перевозки грузов. Большая материалоемкость крышек снижает экономическую эффективность судна, ведет к необходимости использования мощных и массогабаритных средств подъема крышек (для съемных люковых закрытий), либо поворота и передвижения крышек (для шарнирно-откидных закрытий). Целью статьи является существенное снижение материалоемкости крышек люкового закрытия за счет рационального выбора их материала и конструктивного оформления при одновременном обеспечении требуемого уровня их надежности. Параметрическая оптимизация традиционной стальной крышки люкового закрытия сухогрузного судна проекта RSD59 может привести к снижению ее массы не более чем на 15-17. Поэтому для достижения цели работы решается задача оптимизации конструкции алюминиевой крышки на основе комплексного подхода, состоящего в последовательном использовании топологических и параметрических оптимизационных методов и выполнении на последней стадии работы снижения уровня концентрации напряжений путем оптимизации формы узлов крышки. При этом на стадии выбора конструктивно-силовой схемы крышки применяются приёмы топологической оптимизации, на стадии выбора толщин и параметров силовых элементов способы параметрической оптимизации, а на стадии конструктивно-технологического оформления узлов методы оптимизации формы. Выполненные расчетные исследования привели к следующим основным результатам: к выявлению прогрессивных конструктивно-силовых схем и конструктивно-технологических решений, обеспечивающих значительное снижению массы крышек люковых закрытий при умеренных затратах на их изготовление к высоким оценкам эффективности использования современных алюминиевых сплавов для изготовления люковых закрытий, способствующим существенному снижению их материалоемкости (примерно двукратному и более по сравнению с использованием стали), улучшению условий их функционирования и проведения погрузочно-разгрузочных работ на сухогрузных судах к выводу об эффективности использования разработанных конструкторских решений для крышек люковых закрытий при создании перспективных сухогрузных судов.A bulk carrier hatch cover, which provides cargo compartments impermeability and cargo transportation on the cover, as well as safety of bulk carriers and sea cargo transportation in them, is studied. Cover high material consumption decreases vessel profitability, causes the necessity to use either powerful and mass-dimensional cover lifting devices (for removable hatch covers) or covers rotation and movement (for hinged covers). The purpose of this paper consists in considerable decrease of hatch cover material consumption through rational selection of covers material and design at provision of the required covers reliability level. Parametric optimization of a conventional steel cover of RSD59 project bulk carrier could result in cover mass decrease by more than 15 to 17. Therefore, to achieve the work purpose, a problem of aluminum cover structural optimization was solved based on a comprehensive approach that consisted in successive use of topologic and parametric optimization methods and decrease of the stress concentration level at the last step via cover assemblies shape optimization. At that topological optimization methods were applied at the stage of selecting cover structural arrangement parametric optimization methods were applied at the stage of selecting load-carrying elements thickness and parameters, and shape optimization methods were used at the stage of structural and technology design of assemblies. The performed calculation studies resulted in the following: revealing the advanced structural arrangements and design and technology solutions that provide considerable hatch covers mass decrease at reasonable costs for their manufacture high assessment of using advanced aluminum alloys for manufacturing hatch covers that promote considerable decrease of their material consumption (approximately up to twofold or greater in comparison with steel), improving conditions of cover functioning and handling operation in bulk carriers conclusion on effectiveness of using developed design solutions for hatch covers when creating prospective bulk carriers.

scholarly journals ЭФФЕКТИВНОСТЬ МЕТОДОВ ОПРЕДЕЛЕНИЯ ГРУППОВЫХ СИСТЕМ ПРЕДПОЧТЕНИЙ ДИСПЕТЧЕРОВ НА ОПАСНОСТИ ХАРАКТЕРНЫХ ОШИБОК, СОВЕРШАЕМЫХ В ПРОЦЕССЕ УПРАВЛЕНИЯ ВОЗДУШНЫМ ДВИЖЕНИЕМ

2018 ◽  
pp. 93-103
Author(s):  
Алексей Николаевич Рева ◽  
Шахин Шахвели-оглы Насиров ◽  
Бала Мушгюль-оглы Мирзоев
Keyword(s):  
Decision Making ◽  
Parametric Optimization ◽  
Professional Activity ◽  
Air Traffic Controllers ◽  
Main Emphasis ◽  
Decision Making Processes ◽  
Complex Decision Making ◽  
Coefficient Of Concordance ◽  
Complex Decision ◽  
Non Parametric

The human factor problem should be solved by identifying, qualifying and preventing the erroneous actions of the air traffic controllers. It is presented two schemes explaining the structure of human qualimetry factor and the interaction of the components of the ICAO safety concept, where the main emphasis is on an aviation personnel’ attitude to dangerous actions or conditions, which is revealed by the qualimetry of the decision-making processes’ characteristics: the attitude towards risk (the main dominants and fuzzy assessments), levels of claims, dangerous qualities and preferences systems. The preferences systems are considered as ordered characteristics and indicators of professional activity, which are subjectively compared with the positions of influence on flight safety. The spectrum of n = 21 characteristic errors was formed considering the recommendations of ICAO, EUROCONTROL and accident statistics. It is determined that procedures of collecting the information of errors danger contribute their recognition, memorization, and avoidance: controllers who passed the test according to the proposed method before training made by one third fewer errors in its process. Two criteria for assessing group preferences are realized: the level of consensus (known as Kendall’s coefficient of concordance) and the severity of the ranking, determined by the presence of "related" ranks, for which a special indicator is introduced. It is defined that this indicator should be determined both for the sample of respondents and for the preferences group systems of developed with the chosen method of individual opinions’ aggregation. It was performed the comparative analysis of complex decision-making strategies of effectiveness in the construction of a preferences group systems m = 65 controllers: sum and averaging of ranks, classical criteria (Wald's, Savage's and Laplace's criterion), optimal prediction, applying the non-parametric optimization of the preferences group systems. The non-parametric optimization of the group system of pre-readings was carried out by Kemeny median and it was proved that it was the closest to all the results obtained by other methods and strategies

Shape Optimization of Femoral Components of an Artificial Hip Prosthesis Using the Three-Dimensional P-Version Finite Element Study and the In Vitro Measurement of Strain in the Bone Cement

2002 ◽  
Author(s):  
Masaru Higa ◽  
Ikuya Nishimura ◽  
Kazuhiro Matsuda ◽  
Hiromasa Tanino ◽  
Yoshinori Mitamura
Keyword(s):  
Finite Element ◽  
Shape Optimization ◽  
Bone Cement ◽  
Femoral Component ◽  
Three Dimensional ◽  
Femoral Stem ◽  
Cement Mantle ◽  
Optimum Shape ◽  
Shear Stresses

Though Total Hip Arthroplasty (THA) is being performed with greater frequency every year for patients with endstage arthritis of hip, mechanical fatigue of bone cement leading to damage accumulation is implicated in the loosening of cemented hip components. This fatigue failure of bone cement has been reported to be the result of high tensile and shear stresses at the bone cement. The aim of this study is to design the optimum shape of femoral component of a THA that minimizes the peak stress value of maximum principal stress at the bone cement and to validate the FEM results by comparing numerical stress with experimental ones. The p-version three-dimensional Finite Element Method (FEM) combined with an optimization procedure was used to perform the shape optimization. Moreover the strain in the cement mantle surrounding the cemented femoral component of a THA was measured in vitro using strain gauges embedded within the cement mantle adjacent to the developed femoral stem to validate the optimization results of FEM.

Non-parametric Optimization Using Subspace-Based Objective Functions

2021 ◽  
pp. 339-357
Author(s):  
Angelo Aloisio ◽  
Riccardo Cirella ◽  
Massimo Fragiacomo ◽  
Rocco Alaggio
Keyword(s):  
Parametric Optimization ◽  
Objective Functions ◽  
Non Parametric

Development of an Optimization Framework for Parameter Identification and Shape Optimization Problems in Engineering

2011 ◽  
Vol 1 (1) ◽  
pp. 57-79 ◽  
Author(s):  
A. Andrade-Campos
Keyword(s):  
Inverse Problems ◽  
Shape Optimization ◽  
Parameter Identification ◽  
Optimization Problems ◽  
Optimization Methods ◽  
Optimum Shape ◽  
Optimization Framework ◽  
Search Optimization ◽  
Initial Geometry

The use of optimization methods in engineering is increasing. Process and product optimization, inverse problems, shape optimization, and topology optimization are frequent problems both in industry and science communities. In this paper, an optimization framework for engineering inverse problems such as the parameter identification and the shape optimization problems is presented. It inherits the large experience gain in such problems by the SiDoLo code and adds the latest developments in direct search optimization algorithms. User subroutines in Sdl allow the program to be customized for particular applications. Several applications in parameter identification and shape optimization topics using Sdl Lab are presented. The use of commercial and non-commercial (in-house) Finite Element Method codes to evaluate the objective function can be achieved using the interfaces pre-developed in Sdl Lab. The shape optimization problem of the determination of the initial geometry of a blank on a deep drawing square cup problem is analysed and discussed. The main goal of this problem is to determine the optimum shape of the initial blank in order to save latter trimming operations and costs.

scholarly journals Chinese-language digital/social media in Australia: double-edged sword in Australia’s public diplomacy agenda

2019 ◽  
Vol 173 (1) ◽  
pp. 22-35 ◽  
Author(s):  
Wanning Sun
Keyword(s):  
Social Media ◽  
Pilot Study ◽  
Public Diplomacy ◽  
Chinese Language ◽  
Future Research ◽  
Republic Of China ◽  
Cultural Life ◽  
Challenges And Opportunities ◽  
Key Features ◽  
Analytical Frameworks

Using examples from Sydney Today, this article discusses the challenges facing Australia in its attempt to engage diasporic media for the purpose of public diplomacy towards China. Based on a pilot study, the article first reviews some of the major developments in the Chinese-language media in Australia, paying particular attention to the key features of digital/social media since the arrival of migrants from the People’s Republic of China. Second, it presents examples from four key content categories: Australia–China relations, politics, economics, and cultural life. Finally, the article identifies the challenges and opportunities facing Australia’s public diplomacy towards China, and outlines some key methodological and analytical frameworks for future research

scholarly journals Multivariate non-parametric Euclidean distance model for hourly disaggregation of daily climate data

2020 ◽  
Vol 143 (1-2) ◽  
pp. 241-265
Author(s):  
Christina Görner ◽  
Johannes Franke ◽  
Rico Kronenberg ◽  
Olaf Hellmuth ◽  
Christian Bernhofer
Keyword(s):  
Euclidean Distance ◽  
Sunshine Duration ◽  
Future Research ◽  
Climate Projections ◽  
Climate Data ◽  
Diurnal Cycles ◽  
Hourly Data ◽  
Distance Model ◽  
Similar Day ◽  
Non Parametric

AbstractThe algorithm for and results of a newly developed multivariate non-parametric model, the Euclidean distance model (EDM), for the hourly disaggregation of daily climate data are presented here. The EDM is a resampling method based on the assumption that the day to be disaggregated has already occurred once in the past. The Euclidean distance (ED) serves as a measure of similarity to select the most similar day from historical records. EDM is designed to disaggregate daily means/sums of several climate elements at once, here temperature (T), precipitation (P), sunshine duration (SD), relative humidity (rH), and wind speed (WS), while conserving physical consistency over all disaggregated elements. Since weather conditions and hence the diurnal cycles of climate elements depend on the weather pattern, a selection approach including objective weather patterns (OWP) was developed. The OWP serve as an additional criterion to filter the most similar day. For a case study, EDM was applied to the daily climate data of the stations Dresden and Fichtelberg (Saxony, Germany). The EDM results agree well with the observed data, maintaining their statistics. Hourly results fit better for climate elements with homogenous diurnal cycles, e.g., T with very high correlations of up to 0.99. In contrast, the hourly results of the SD and the WS provide correlations up to 0.79. EDM tends to overestimate heavy precipitation rates, e.g., by up to 15% for Dresden and 26% for Fichtelberg, potentially due to, e.g., the smaller data pool for such events, and the equal-weighted impact of P in the ED calculation. The OWPs lead to somewhat improved results for all climate elements in terms of similar climate conditions of the basic stations. Finally, the performance of EDM is compared with the disaggregation tool MELODIST (Förster et al. 2015). Both tools deliver comparable and well corresponding results. All analyses of the generated hourly data show that EDM is a very robust and flexible model that can be applied to any climate station. Since EDM can disaggregate daily data of climate projections, future research should address whether the model is capable to respect and (re)produce future climate trends. Further, possible improvements by including the flow direction and future OWPs should be investigated, also with regard to reduce the overestimation of heavy rainfall rates.

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