Search results

The indefinite nature of the mixed finite element formulation of the Navier‐Stokes equations is treated by segregation of the variables. The segregation algorithm assembles the coefficients which correspond to the velocity variables in the upper part of the equation matrix and the coefficients which corresponds to the pressure variables in the lower part of the equation matrix. During the incomplete; elimination of the velocity matrix, fill‐in will occur in the pressure matrix, hence, divisions with zero are avoided. The fill‐in rule applied here is related to the location of the node in the finite element mesh, rather than the magnitude of the fill‐in or the magnitude of the coefficient at the location of the fill‐in. Different orders of fill‐in are explored for ILU preconditioning of the mixed finite element formulation of the Navier‐Stokes equations in two dimensions.

In this work, it is presented a locally conservative multiscale algorithm accounting the mineralization process during the supercritical carbon dioxide injection into a deep saline aquifer. The purpose of this study is to address numerically the geological storage of CO₂ in a highly heterogeneous reservoir, leading with interactions among several phenomena in multiple scales.

This algorithm have features that distinguish it from the presently available solvers which are: (i) an appropriate combination of a coupled transport system solver using a high-order non-oscillatory central-scheme finite volume method and, elliptic numerical approach applying a locally conservative finite element method for Darcy’s law and, (ii) the capability of leading with interactions among several phenomena in multiple scales.

As a result, this approach was able to quantify the precipitation of the carbonate crystals at the solid interface.

Gives a bibliographical review of the error estimates and adaptive finite element methods from the theoretical as well as the application point of view. The bibliography at the end contains 2,177 references to papers, conference proceedings and theses/dissertations dealing with the subjects that were published in 1990‐2000.

Bandwagon refers to the adoption of popular ideas, thoughts, or practices. Although the inter-organizational (macro) dynamics of the phenomenon have been widely studied, its intra-organizational (micro) aspects have received limited attention. The paper presents a theoretical framework and a model that address intra-organizational aspects of bandwagon drawing on distributed cognition, social relationships, and other elements of the organizational structure such as culture and defensive routines. The analysis of simulated data from the model suggests that the phenomenon is likely to decrease with highly informal culture, promotion of advice taking and giving, low levels of distrust, strong social ties, and minimal defensive routines.

The purpose of this paper is to explore citizens’ willingness to invest in photovoltaics.

To meet the aim of the research, a questionnaire survey was conducted in the island of Evia in Greece using the method of random stratified sampling. A total of 366 responses were analyzed using both descriptive and inductive statistics methods, such as principal components analysis, K-means cluster analysis, discriminant analysis and binary logistic regression.

The research results indicate that 73per cent of the respondents would invest in renewable energy sources, whereas 55per cent of them would specifically invest in photovoltaics. Regarding their views on photovoltaics, three components were extracted; photovoltaics positive effects, facilitations for investments in photovoltaics and photovoltaics’ performance. Area of residence, annual income and the above-mentioned three components of views on photovoltaics were found to be statistically significant for the dichotomous variable of willingness to invest in photovoltaics. Among the examined variables, photovoltaics performance found to contribute the most in increasing respondents’ willingness to invest in photovoltaics.

The study filled the literature gap concerning citizens’ willingness to invest in photovoltaics in Greece. Furthermore, the research results made feasible to understand the factors that can lead in an investment decision for photovoltaics.

Herbert Simon introduced the term “docility” to define the tendency of human beings to get information from social channels. In this paper, we enrich this first definition with distributed cognition based arguments, and suggest that docile individuals modify the information they get, before passing it on to others. We present a simulation model of docile and non-docile individuals in organizations, where different docility attitudes (behaviors) are considered. In standard conditions, findings suggest that the above-average docile individuals remain below 20% of the number of workers in a given organization. This way, we outline potentials and limits of this intriguing concept.

This paper aims to develop a meshfree algorithm based on local radial basis functions (RBFs) combined with the differential quadrature (DQ) method to provide numerical approximations of the solutions of time-dependent, nonlinear and spatially one-dimensional reaction-diffusion systems and to capture their evolving patterns. The combination of local RBFs and the DQ method is applied to discretize the system in space; implicit multistep methods are subsequently used to discretize in time.

In a method of lines setting, a meshless method for their discretization in space is proposed. This discretization is based on a DQ approach, and RBFs are used as test functions. A local approach is followed where only selected RBFs feature in the computation of a particular DQ weight.

The proposed method is applied on four reaction-diffusion models: Huxley’s equation, a linear reaction-diffusion system, the Gray–Scott model and the two-dimensional Brusselator model. The method captured the various patterns of the models similar to available in literature. The method shows second order of convergence in space variables and works reliably and efficiently for the problems.

The originality lies in the following facts: A meshless method is proposed for reaction-diffusion models based on local RBFs; the proposed scheme is able to capture patterns of the models for big time T; the scheme has second order of convergence in both time and space variables and Nuemann boundary conditions are easy to implement in this scheme.

The purpose of this paper is to explain why finding a theory for futures studies is such a demanding task. In particular, the paper paves the way towards a theoretical framework that goes beyond both positivism and anti‐positivism.

The paper discusses a network of mutually interlinked concepts, including: levels of reality; parts and wholes; causation; the multiplicity of times; anticipation; the thick present; and latents.

The paper presents the two main obstructions blocking the way towards a theory for futures studies (namely, the belief that the opposition between positivists and anti‐positivists is exhaustive, and the need for better connections with other sciences such as biology, cognitive science and the social sciences.

The paper discusses only one of the different threads in the elaboration of a theoretical basis for futures studies, namely the components closer to science.

A proper theory for futures studies will contribute to making them more robust and efficient.

The general framework presented by the paper extends well beyond the somewhat restricted field of futures studies and includes social and psychological sciences, together with biology.

The purpose of this paper is to present a methodology for medical robot kinematics design developed using a knowledge‐management approach.

A classification of medical robots is proposed based on their kinematic characteristics and 76 robot specifications were collected in a catalogue. Then, having drawn a generic specifications sheet, rules were proposed to choose a structure from these specifications.

Findings are situated at several levels: the catalogue, the classification of robots with respect to their kinematic characteristics, a generic and specific specifications sheet, and an organigram to choose the most relevant structure from the specifications.

This structural synthesis represents a preliminary step in the design of medical robots which will be completed by an additional dimensional synthesis.

This work offers a new methodology for medical robots design distinct from what is usually done for medical or industrial robots design using intuition, expertise and non‐formal knowledge.

The purpose of this paper is to discuss a technique of restoring data from a broken/damaged near-field communication (NFC) tag whose coil is damaged and seems unrecoverable.

This paper discusses a method to restore data from damaged NFC tags by designing a coil that matches the technical specification of NFC for restoring information. In this paper, an NFC tag with a broken antenna coil and its operational NFC chip is used for restoring data by making an external loop antenna for the same chip.

If the NFC tag is damaged, the information stored on the tag can be lost and can cause serious inconvenience. This research provides an excellent mechanism for retrieving all the information accurately from a damaged NFC tag provided the NFC chip is not damaged.

One of the major limitations of this research is that the NFC chip remains intact without any damages. Data can only be recoverable if just the antenna of the NFC tag is damaged; any damage to the NFC chip would make it impossible for the data to be recoverable.

The research is carried out with limited resources in an academic institute and hence cannot be compared to antenna designs of the industry. Furthermore, industry vendors are using aluminum to design the coil; however, in this study a copper coil is used for coil design since it is far less expensive than aluminum coil.

NFC is a rather new short-range wireless technology and not much work is done in this field as far as antenna study is concerned. This study brings a technique to design a coil antenna for a damaged NFC tag to retrieve all the information without losing even a single bit of sensitive information.