There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

This chapter introduces the finite element method (FEM) as a tool for solution of classical electromagnetic problems. Although we discuss the main points in the application of the finite element method to electromagnetic design, including formulation and implementation, those who seek deeper understanding of the finite element method should consult some of the works listed in the bibliography section.

Introduction to the Finite Element Method

This chapter introduces the subject of statistical pattern recognition (SPR). It starts by considering how features are defined and emphasizes that the nearest neighbor algorithm achieves error rates comparable with those of an ideal Bayes’ classifier. The concepts of an optimal number of features, representativeness of the training data, and the need to avoid overfitting to the training data are stressed. The chapter shows that methods such as the support vector machine and artificial neural networks are subject to these same training limitations, although each has its advantages. For neural networks, the multilayer perceptron architecture and back-propagation algorithm are described. The chapter distinguishes between supervised and unsupervised learning, demonstrating the advantages of the latter and showing how methods such as clustering and principal components analysis fit into the SPR framework. The chapter also defines the receiver operating characteristic, which allows an optimum balance between false positives and false negatives to be achieved.

Statistical Pattern Recognition

This study provides a bibliographic review in the broad field of green composites seeking-out for materials with a potential to be applied in the near future on automotive body panels. Hereupon, materials deriving from renewable resources will be preferred as opposed to the exhaustible fossil products. With the technical information of bio-polymers and natural reinforcements a database was created with the mechanical performance of several possible components for the prospect green composite. Following the review, an assessment is performed where aspects of suitability for the candidate elements in terms of mechanical properties are analyzed. In that section, renewable materials for matrix and reinforcement are screened accordingly in order to identify which hold both adequate strength and stiffness performance along with affordable cost so as to be a promising proposal for a green composite.

Green composites: A review of adequate materials for automotive applications

http://jultika.oulu.fi/files/nbnfi-fe2017112150815.pdf

One-part alkali-activated materials : a review

Ultrasonic Propagation Imaging or Acoustic Wavefield Imaging has been widely used to evaluate structural damages and internal features. Inspecting complete wavefield time history for damage identification is tedious and error-prone. A more effective way is by extracting damage-related information into a single image. A wavefield velocity imaging method that maps the local estimates of group or phase velocity is proposed. Actual velocity values rather than arbitrarily-scaled intensities are mapped, enabling damage sizing without the need of supervised training or inspecting wavefield propagation video. Performance of the proposed method was tested by inspecting a 100 mm by 100 mm area of a 2 mm thick stainless steel specimen. Local phase velocity maps of A0 mode showed a half-thickness hole of 2 mm diameter as significant change in local phase velocity from the nominal 2 m/ms. Full width at half maximum of relevant velocity profiles proved the accuracy and consistency of the damage sizing.

Local wavefield velocity imaging for damage evaluation

Composite structures and materials are used in aerospace, marine and automotive applications due to their light weight characteristics By using rice husk ash (RHA) as natural binder to replace epoxy resin, it improves the characteristic of the composite laminated structure Rice husk has become an important ingredient in silica, silicon carbide, and silicon nitride because of its high a silicon content This paper evaluates the performance of laminated composite plate in a drop-weight impact testing Two plates are attached to the test rig in the particular desired impact orientation The main advantages of this process are the plates provide more realistic drop-weight impact and data Data from the impact test was collected and analysed to evaluate the material properties of epoxy resin and RHA Results show RHA's energy absorption is better and it has more deformation to prevent structure failures compared with epoxy resin This paper aims to evaluate the application of RHA as a geopolymer binder and flax fibre as an alternative material to glass fibre in the composites industry

Drop-weight impact test on laminated composite plate of flax (Linum usitatissimum) using rice husk ash from paddy (Oryza sativa) as a natural binder

The purpose of this work is to present a new analytical model for predicting the perforation characteristics of multi–layered transparent polymer materials. In type polycarbonate and impacted by rigid steel conical tip projectiles in the range of 100–970 m/s of impact velocity. Analytical model has been presented for all energy absorbing mechanism. It was assumed that the energy is equated as loss of the kinetic energy of the projectile and assumed to be classified into three types which include elastic work, petaling work done and dishing work done. The analytical predictions were in good agreement with existing experimental results.

http://ijet.feiic.org/journals/2011%20Issue%202%20-%2010.pdf

Ballistic limit behavior of polymers transparent materials under high velocity impact

A process based on powder metallurgy approach was developed to produce open celled aluminium foam. In the preparation of foam specimens, the Al powder and the NaCl (leaching agent) were dry mixed together in order to prepare a homogeneous mixture. The blended mixture was then subjected to pressure assisted sintering in which a pressure beyond atmospheric level is externally applied to the specimen during high frequency induction heated sintering. The embedded leaching agent was then dissolved in order to leave behind an open celled Al with the same chemical composition as that of the original Al powder. The final material is highly porous and has an interconnected porosity network. The structure of the resulting material has three levels of porosity (i.e. main cells, windows and microporosity). The X-ray diffraction analysis shows that, as the content of NaCl is increased to the volume fraction of 60%, no traces of NaCl presents in the foam.

Fabrication of aluminium foam through pressure assisted high frequency induction heated sintering dissolution process: an experimental observation

The competition trend within the electricity segment has motivated the research community efforts and directed them towards investigations of deregulation of the electricity markets. This underlines significant research needs to insure providing appropriate design and functioning, as well as analysis support models that would fit to recent electricity market settings. Thus, this work focuses on facets of the deregulated electricity markets and on modeling the power market. It aims primarily at identifying, classifying and characterizing the quite bewildering multiplicity of the methods available in the specialized literature on the topic. This study offers review of the most appropriate works related to electricity market models, like the equilibrium and non-equilibrium models, and some other related areas of research, like optimization as an exogenic variable or firm decisions function. The agent and Cournot based supply function has non-equilibrium and equilibrium simulation models under the conditions of both imperfect and perfect competition. Lastly, it characterizes the approaches most suitable for implementing different types of market analysis and planning studies in the electricity sector for new setting.

	 

	 

	Key words: Electricity market deregulation, equilibrium and non-equilibrium market models, market behavior.

Faizal Mustapha

Papers

Local wavefield velocity imaging for damage evaluation

Drop-weight impact test on laminated composite plate of flax (Linum usitatissimum) using rice husk ash from paddy (Oryza sativa) as a natural binder

Ballistic limit behavior of polymers transparent materials under high velocity impact

Fabrication of aluminium foam through pressure assisted high frequency induction heated sintering dissolution process: an experimental observation

Equilibrium and non-equilibrium models of the power markets