scholarly journals Overhang control in topology optimization: a comparison of continuous front propagation-based and discrete layer-by-layer overhang control

2021 ◽  
Author(s):  
Emiel van de Ven ◽  
Robert Maas ◽  
Can Ayas ◽  
Matthijs Langelaar ◽  
Fred van Keulen
Keyword(s):  
Topology Optimization ◽  
Front Propagation ◽  
Layer By Layer ◽  
Design Rules ◽  
Advantages And Disadvantages ◽  
Overhang Angle ◽  
Design Freedom ◽  
Continuous Setting ◽  
Discrete Layer ◽  
Made In

AbstractAlthough additive manufacturing (AM) allows for a large design freedom, there are some manufacturing limitations that have to be taken into consideration. One of the most restricting design rules is the minimum allowable overhang angle. To make topology optimization suitable for AM, several algorithms have been published to enforce a minimum overhang angle. In this work, the layer-by-layer overhang filter proposed by Langelaar (Struct Multidiscip Optim 55(3):871–883, 2017), and the continuous, front propagation-based, overhang filter proposed by van de Ven et al. (Struct Multidiscipl Optim 57(5):2075–2091, 2018) are compared in detail. First, it is shown that the discrete layer-by-layer filter can be formulated in a continuous setting using front propagation. Then, a comparison is made in which the advantages and disadvantages of both methods are highlighted. Finally, the continuous overhang filter is improved by incorporating complementary aspects of the layer-by-layer filter: continuation of the overhang filter and a parameter that had to be user-defined are no longer required. An implementation of the improved continuous overhang filter is provided.

ICO as a Business Financing Tool: Myths and Reality

2018 ◽  
Vol 11 (2) ◽  
pp. 41-51 ◽  
Author(s):  
I. Ya. Lukasevich
Keyword(s):  
Corporate Finance ◽  
Digital Economy ◽  
Real Sector ◽  
The Real ◽  
Objective Information ◽  
Advantages And Disadvantages ◽  
Russian Economy ◽  
The Subject ◽  
Business Financing ◽  
Made In

The subject of the research is new tools for business financing using the initial coin offering (ICO) in the context of the development of cryptocurrencies and the blockchain technologies as their basis. The purpose of the work was to analyze the advantages and disadvantages of the ICO in comparison with traditional financial tools as well as prospects, limitations and problems of using digital financial tools. Conclusions are made in relation to possibilities, limitations and application areas of digital business financing tools, particularly in the real sector, taking into account the specifics of the Russian economy and legislation. It is shown that the main problems of using the digital financial tools are related to the economic sphere and caused by the lack of adequate approaches to evaluation of assets as well as the shortage of objective information. The problems and new tasks of corporate finance in the digital economy are defined.

Inflammatory Markers Associated With Diabetes Mellitus – Old and New Players

2020 ◽  
Vol 26 ◽  
Author(s):  
Emir Muzurović ◽  
Zoja Stanković ◽  
Zlata Kovačević ◽  
Benida Šahmanović Škrijelj ◽  
Dimitri P Mikhailidis
Keyword(s):  
Diabetes Mellitus ◽  
Inflammatory Markers ◽  
High Specificity ◽  
Future Directions ◽  
Effective Strategies ◽  
Advantages And Disadvantages ◽  
Type 2 Dm ◽  
Increased Risk ◽  
Made In

: Diabetes mellitus (DM) is a chronic and complex metabolic disorder, and also an important cause of cardiovascular (CV) diseases (CVDs). Subclinical inflammation, observed in patients with type 2 DM (T2DM), cannot be considered the sole or primary cause of T2DM in the absence of classical risk factors, but it represents an important mechanism that serves as a bridge between primary causes of T2DM and its manifestation. Progress has been made in the identification of effective strategies to prevent or delay the onset of T2DM. It is important to identify those at increased risk for DM by using specific biomarkers. Inflammatory markers correlate with insulin resistance (IR) and glycoregulation in patients with DM. Also, several inflammatory markers have been shown to be useful in assessing the risk of developing DM and its complications. However, the intertwining of pathophysiological processes and the not-quite-specificity of inflammatory markers for certain clinical entities limits their practical use. In this review we consider the advantages and disadvantages of various inflammatory biomarkers of DM that have been investigated to date as well as possible future directions. Key features of such biomarkers should be high specificity, non-invasiveness and cost-effectiveness.

scholarly journals A STRUCTURED APPROACH TO REDUCE DESIGN ITERATIONS IN ADDITIVE MANUFACTURING

2021 ◽  
Vol 1 ◽  
pp. 231-240
Author(s):  
Laura Wirths ◽  
Matthias Bleckmann ◽  
Kristin Paetzold
Keyword(s):  
Additive Manufacturing ◽  
Spare Parts ◽  
Design Guidelines ◽  
Final Part ◽  
Layer By Layer ◽  
Powder Bed ◽  
Batch Sizes ◽  
Manufacturing Technologies ◽  
Structured Approach ◽  
Design Freedom

AbstractAdditive Manufacturing technologies are based on a layer-by-layer build-up. This offers the possibility to design complex geometries or to integrate functionalities in the part. Nevertheless, limitations given by the manufacturing process apply to the geometric design freedom. These limitations are often unknown due to a lack of knowledge of the cause-effect relationships of the process. Currently, this leads to many iterations until the final part fulfils its functionality. Particularly for small batch sizes, producing the part at the first attempt is very important. In this study, a structured approach to reduce the design iterations is presented. Therefore, the cause-effect relationships are systematically established and analysed in detail. Based on this knowledge, design guidelines can be derived. These guidelines consider process limitations and help to reduce the iterations for the final part production. In order to illustrate the approach, the spare parts production via laser powder bed fusion is used as an example.

Numerical Experiments in Using Voronoi Cell Finite Elements for Topology Optimization

2009 ◽  
Author(s):  
James M. Gibert ◽  
Georges M. Fadel
Keyword(s):  
Topology Optimization ◽  
Isotropic Material ◽  
Numerical Experiments ◽  
Voronoi Cell ◽  
Material Model ◽  
Topological Optimization ◽  
Advantages And Disadvantages ◽  
Compliance Minimization ◽  
Design Variables ◽  
Standard Linear

This paper provides two separate methodologies for implementing the Voronoi Cell Finite Element Method (VCFEM) in topological optimization. Both exploit two characteristics of VCFEM. The first approach utilizes the property that a hole or inclusion can be placed in the element: the design variables for the topology optimization are sizes of the hole. In the second approach, we note that VCFEM may mesh the design domain as n sided polygons. We restrict our attention to hexagonal meshes of the domain while applying Solid Isotropic Material Penalization (SIMP) material model. Researchers have shown that hexagonal meshes are not subject to the checker boarding problem commonly associated with standard linear quad and triangle elements. We present several examples to illustrate the efficacy of the methods in compliance minimization as well as discuss the advantages and disadvantages of each method.

Adhesives in engineering

1997 ◽  
Vol 211 (5) ◽  
pp. 307-335 ◽  
Author(s):  
A J Kinloch
Keyword(s):  
Molecular Weight ◽  
Fracture Mechanics ◽  
Service Life ◽  
Adhesive Joint ◽  
Adhesive Joints ◽  
Liquid Form ◽  
Engineering Applications ◽  
Advantages And Disadvantages ◽  
Load Carrying ◽  
Made In

When considering methods for joining materials, there are many advantages that engineering adhesives can offer, compared to the more traditional methods of joining such as bolting, brazing, welding, mechanical fasteners, etc. The advantages and disadvantages of using engineering adhesives are discussed and it is shown that it is possible to identify three distinct stages in the formation of an adhesive joint. Firstly, the adhesive initially has to be in a ‘liquid’ form so that it can readily spread over and make intimate molecular contact with the substrates. Secondly, in order for the joint to bear the loads that will be applied to it during its service life, the ‘liquid’ adhesive must now harden. In the case of adhesives used in engineering applications, the adhesive is often initially in the form of a ‘liquid’ monomer which polymerizes to give a high molecular weight polymeric adhesive. Thirdly, it must be appreciated that the load-carrying ability of the joint, and how long it will actually last, are affected by: (a) the design of the joint, (b) the manner in which loads are applied to it and (c) the environment that the joint encounters during its service life. Thus, to understand the science involved and to succeed in further developing the technology, the skills and knowledge from many different disciplines are required. Indeed, the input from surface chemists, polymer chemists and physicists, materials engineers and mechanical engineers are needed. Hence, the science and technology of adhesion and adhesives is a truly multidisciplined subject. These different disciplines have been brought together by developing a fracture mechanics approach to the failure of adhesive joints. The advances that have been made in applying the concepts of fracture mechanics to adhesive joints have enabled a better understanding of the fundamental aspects of adhesion and the more rapid extension of adhesives technology into advanced engineering applications.

Interaction between Mobile Agents and Web Services

2009 ◽  
pp. 717-725 ◽  
Author(s):  
Kamel Karoui
Keyword(s):  
Web Services ◽  
Mobile Agents ◽  
Message Passing ◽  
Synchronous Mode ◽  
Advantages And Disadvantages ◽  
Enterprise Javabeans ◽  
Message Service ◽  
Local Host ◽  
The Web ◽  
Made In

With the interconnection of computers in networks, particularly through the Internet, it becomes possible to connect applications on distant computers. An application works perfectly whether it isdistant or local. Moreover, a distant applicationallows us to benefit from the following additional advantages: • Data and processes can be stored on a remote server that has a bigger storage capacity than the local host. Data can be shared between users using, for example, Remote Procedure Call (RPC), Remote Method Invocation (RMI), Java Message Service (JMS), and Enterprise JavaBeans (EJB) (Frénot, 2000): • Distant application can be used at the same time by several users; • Updating data and processes can be done only in one host; • Flexibility on distribution of the load: An application can be executed on the available machine; and • High availability: A faulty machine does not affect the others. Many approaches have been proposed and developed for communication between distant hosts on a network such as Message Passing (MP), Remote Evaluation (REV), Remote Object Invocation (ROI), Mobile Agents (MA), Common Object Request Broker Architecture (CORBA), Web Services (WS), RPC, and RMI (Dejan, LaForge, & Chauhan, 1998). In this article, we will focus on two particular paradigms: The Web Services and the Mobile Agents. WS defines a standard to invoke distant applications and to recover results across the Web. Its invocation is made in synchronous mode. MA has the faculty to move easily between a network’s hosts to execute user requests. MA communication is made in asynchronous mode. The fusion of these two complementary technologies will solve many problems. This article is composed of the following sections: In the first two sections, we introduce the concepts of WS and MA, their advantages and disadvantages. In the third section, we present different kinds of interaction between MA and WS. Finally, we study an example in the last section.

scholarly journals The Application of Third Generation Semiconductor in Power Industry

2020 ◽  
Vol 198 ◽  
pp. 04011
Author(s):  
Yuqian Zhang
Keyword(s):  
Future Development ◽  
First Generation ◽  
Rapid Development ◽  
Physical Characteristics ◽  
Third Generation ◽  
Power Switching ◽  
Advantages And Disadvantages ◽  
The Third ◽  
Great Possibility ◽  
Made In

With the rapid development of technologies, the third generation semiconductor is being studied, as it is leading to the significant change in industry like the manufacture of PC, mobile devices, lighting etc. Till now, due to its irreplaceable physical characteristics, third generation semiconductor is applied to lots of fields. This paper analyzes the application of third generation semiconductor, namely, GaN and SiC. Their characteristics including advantages as well as disadvantages will be discussed through reviewing the result of relevant researches. Meanwhile, comparison between the third generation semiconductors and the second as well as the first generation semiconductors is made in this paper. Through the comparison of physical characteristics, recent marketing, production and limitations, the advantages and disadvantages of each semiconductor is analyzed and the suggestion of how to avoid the disadvantage through application is proposed. At last, the future development is predicted. According to the analysis result of this paper, silicon poses more merits. Silicon is not only cheaper but also performs better making it a preference of GaAs, and GaN in the domain of IC. The second generation semiconductor, GaAs, is widely used in the circuits and photoelectric integration. Furthermore, the third semiconductor material GaN is a promising material for power switching and communication and has the great possibility to play a crucial role in market.

scholarly journals Towards effective advertising regulation: A comparison of UK, Australian and South African schemes

2002 ◽  
Vol 33 (4) ◽  
pp. 1-12 ◽  
Author(s):  
D. Harker ◽  
S. Cassim
Keyword(s):  
South African ◽  
Self Regulation ◽  
Original Form ◽  
Advantages And Disadvantages ◽  
The Past ◽  
Advertising Regulation ◽  
Fundamental Process ◽  
Regulatory Approach ◽  
The Uk ◽  
Made In

The regulation of advertising is a controversial and difficult process, and many schemes around the world opt for a self-regulatory approach to curb unacceptable advertising. However, when schemes are established or reformulated, most countries learn from other, more established, regimes. Whilst Australia and South Africa commenced the advertising self-regulation (ASR) process at similar times and based their systems on the UK model, two attempts have been made in Australia over the past three decades to produce more acceptable ads, whilst South Africa’s system has endured in its original form. This paper reviews the ASR systems in these three countries, using a macro framework for analysis which contextualises advertising in society. The systems have the fundamental process of handling complaints about advertising in common, however there are advantages and disadvantages of each and these are discussed with a view to providing some guidance for Australia’s fledgling, reformulated, system. Important insights for the development of regulation of advertising are presented.

scholarly journals Selecting the most effective alternative of waterproofing membranes for multifunctional inverted flat roofs

2017 ◽  
Vol 23 (5) ◽  
pp. 650-660 ◽  
Author(s):  
Darius KALIBATAS ◽  
Vytautas KOVAITIS
Keyword(s):  
Game Theory ◽  
Evaluation Method ◽  
Effective Alternative ◽  
Advantages And Disadvantages ◽  
Multi Criteria Evaluation ◽  
Flat Roofs ◽  
Made In

There are many various methods, techniques and materials for constructing multifunctional inverted flat roofs now. However, in practice, the constructed roofs of this type often have various defects, whose elimination is rather costly. To solve this problem, the analysis of multifunctional inverted flat roofs has been performed and their advantages and disadvantages, as well as building defects and mistakes made in the course of construction, have been demonstrated. Damp-proofing materials available on the market for making waterproofing membranes for multifunctional inverted flat roofs have been evaluated. The problem of choosing the most effective membrane alternative for the investigated type of roofs is solved by analysing ten alternatives with the help of multi-criteria evaluation method, SAW and three game theory rules determined by Hurwicz, Laplace and Bayes, as well as LEVI 3.0 program. The analysis of the results has shown that the alternative No. 5 is the best membrane alternative among the ten considered options.

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