Porosity control of in situ forming tungsten carbide in laser additive manufacturing (LAM)

© 2020 Old City Publishing, Inc. Published by license under the OCP Science imprint, a member of the Old City Publishing Group.The effect of powder compression on the formation of porosity when heating with a laser beam has been investigated. The starting materials were elemental powders of Fe, W and C which were locally melted to form WC in Fe matrix by an in situ laser additive manufacturing (LAM) process. The resulting microstructures have been studied and chemical analysis has been performed. The main application for the process is for the production of WC based or carbide cutting tooling by very accurate deposition of hard-facing materials onto a steel substrate. Fe is used as the matrix material since ferrous alloys are employed as the substrate for these applications.Peer reviewe

An evaluation methodology for ergonomic design of electronic consumer products based on fuzzy axiomatic design

This article is posted with permission of OCP Science imprint. Copyright @ 2008 Old City Publishing Group.The development life cycle of software and electronic products has been shortened by the growth of rapid prototyping techniques. The evaluation of electronic consumer products should consider hardware and software as well as the ergonomic usability, emotional appeal and aesthetic integrity of the design. This research follows a systematic approach to develop an evaluation methodology for electronic mobile products on ergonomic design. The proposed methodology is based on fuzzy multi attribute decision making and fuzzy axiomatic design realized in three steps; determination of ergonomic attributes for electronic consumer products, determination of a representative set of alternatives, and selection of the best alternative in terms of ergonomic design by utilizing fuzzy axiomatic design. A case study is also provided to support the proposed methodology

Fuzzy rule-based system applied to risk estimation of cardiovascular patients

Cardiovascular decision support is one area of increasing research interest. On-going collaborations between clinicians and computer scientists are looking at the application of knowledge discovery in databases to the area of patient diagnosis, based on clinical records. A fuzzy rule-based system for risk estimation of cardiovascular patients is proposed. It uses a group of fuzzy rules as a knowledge representation about data pertaining to cardiovascular patients. Several algorithms for the discovery of an easily readable and understandable group of fuzzy rules are formalized and analysed. The accuracy of risk estimation and the interpretability of fuzzy rules are discussed. Our study shows, in comparison to other algorithms used in knowledge discovery, that classifcation with a group of fuzzy rules is a useful technique for risk estimation of cardiovascular patients. © 2013 Old City Publishing, Inc

Strong fuzzy subsethood measures and strong equalities via implication functions

In this work we present the definition of strong fuzzy subsethood measure as a unifiying concept for the different notions of fuzzy subsethood that can be found in the literature. We analyze the relations of our new concept with the definitions by Kitainik ( [20]), Young ( [26]) and Sinha and Dougherty ( [23]) and we prove that the most relevant properties of the latter are preserved. We show also several construction methods. © 2014 Old City Publishing, Inc

Biological computing using perfusion anodophile biofilm electrodes (PABE)

This paper presents a theoretical approach to biological computing, using biofilm electrodes by illustrating a simplified Pavlovian learning model. The theory behind this approach was based on empirical data produced from a prototype version of these units, which illustrated high stability. The implementation of this system into the Pavlovian learning model, is one example and possibly a first step in illustrating, and at the same time discovering its potential as a computing processor. © 2007 Old City Publishing, Inc

Exploring a Cognitive Basis for Learning Spatial Relationships with Augmented Reality

Augmented reality (AR) is an emergent class of interface that presents compelling possibilities for advancing spatial visualization. We offer a brief overview of AR technology and current research with in the educational realm. AR interfaces appear to provide a unique combination of visual display properties, modes of user manipulation, and interaction with spatial information. Drawing upon aspects of proprioception and sensorimotor function, we discuss how AR may have a unique and powerful link to spatial knowledge acquisition through visuo-motor involvement in the processing of information. We identify key properties of AR interfaces and how they differ from conventional visualization interfaces, followed by a discussion of theoretical perspectives that make a case for learning spatial relationships using first person manipulative AR.Recent research provides evidence that this form of AR holds cognitive advantages for learning when compared with traditional desktop 2D interfaces. We review the visual-physical connections to learning using first person manipulative AR within educational contexts. We then provide some suggestions for building future research in this area and explore its significance in the realm of spatial knowledge acquisition

Wet environmental conditions affecting narrow band on-body communication channel for WBANs

© 2018 Old City Publishing, Inc. Wireless Body Area Networks (WBANs) are rising as the key building blocks of next generation networks in modern health care systems. Research in recent years has focused on channel modelling, energy conservation and design of efficient Medium Access Control (MAC) schemes for WBANs. However, less attention has been paid to the on-body channel propagation analysis. This paper presents the propagation effects of wet clothing on the on-body channel at 0.9GHz, 1.8GHz and 2.5GHz and is germane to signal budgets in body-centric and mobile communication systems. A number of transmission measurements between simple monopoles above a square ground plane, placed on the opposing shoulder and hip, wearing single and multi-layered “rainwater wet” and dry cotton T-Shirts for standing, bending, torso left and right are used to gain insight into general levels of the effect of rainwater on propagation. Measured results are statistically processed to extract the level of transmission enhancement due to a wet on-body channel. Results show that wet clothing is generally beneficial to the channel at popular mobile communications frequencies

Complex dynamics of elementary cellular automata emerging from chaotic rules

We show techniques of analyzing complex dynamics of cellular automata (CA) with chaotic behaviour. CA are well known computational substrates for studying emergent collective behaviour, complexity, randomness and interaction between order and chaotic systems. A number of attempts have been made to classify CA functions on their space-time dynamics and to predict behaviour of any given function. Examples include mechanical computation, \lambda{} and Z-parameters, mean field theory, differential equations and number conserving features. We aim to classify CA based on their behaviour when they act in a historical mode, i.e. as CA with memory. We demonstrate that cell-state transition rules enriched with memory quickly transform a chaotic system converging to a complex global behaviour from almost any initial condition. Thus just in few steps we can select chaotic rules without exhaustive computational experiments or recurring to additional parameters. We provide analysis of well-known chaotic functions in one-dimensional CA, and decompose dynamics of the automata using majority memory exploring glider dynamics and reactions

Hyperbolic tilings and formal language theory

In this paper, we try to give the appropriate class of languages to which belong various objects associated with tessellations in the hyperbolic plane.Comment: In Proceedings MCU 2013, arXiv:1309.104