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Found 6289 publications

Prioritisation of Nielsen’s usability heuristics for user interface design using fuzzy cognitive maps

Muhanna Muhanna Rita N. Amro Saransh Dhama L. T. Kóczy

Publication Name: Communications in Computer and Information Science

Publication Date: 2018-01-01

Volume: 853

Issue: Unknown

Page Range: 511-522

Description:

Usability Heuristics are being widely used as a means of evaluating user interfaces. However, little existing work has been done that focused on assessing the effect of these heuristics individually or collectively on said systems. In this paper, the authors propose an approach to evaluating the usability of systems that deploys a prioritised version of Nielsen’s usability heuristics. Fuzzy cognitive maps were used to prioritise the original heuristics according to experts in both fields. Using either set of heuristics evaluators can identify the same number of usability issues. However, when trying to enhance the overall usability of a system, the prioritised set of heuristics can help stakeholders focus their limited resources on fixing the subset of issues that collectively has the worst effect on the usability of their systems during each iteration. To test the findings proposed by authors several websites were evaluated for various usability problems. The experimental results show that by using the proposed heuristics, evaluators were able to find a comparable number of problems to those who used Nielsen’s, the prioritised heuristics resulted in an ordered list of issues based on their effect on usability. Therefore, the authors believe that heuristic evaluation in general, and their introduced heuristics in particular, are effective in dealing with issues when facing situations of limited resources.

Open Access: Yes

DOI: 10.1007/978-3-319-91473-2_44

Evaluation of fair-faced concrete surfaces using digital image processing

Kitti Karolyfi Ferenc Papp

Publication Name: Proceedings of the 12th Fib International Phd Symposium in Civil Engineering

Publication Date: 2018-01-01

Volume: Unknown

Issue: Unknown

Page Range: 1003-1010

Description:

In modern architecture concrete is increasingly used as a design feature as well as for its mechanical properties. Therefore, today's concrete architecture is characterized by various forms, textures and high surface quality. The exact determination of the surface quality requirements is crucial for being able to substantiate any deficiencies of the completed surface if necessary. According to the German, Austrian and Hungarian standards there are four concrete classes distinguished based on several aspects, such as porosity, discoloration, texture, etc. However, the standardized assessment methodologies for fair-faced concrete surfaces are mainly based on manual methods and several aspects can be evaluated only subjectively. The goal of the present study is to propose an objective method for the evaluation of the surface void ratio using photogrammetry and digital image processing techniques. The goal of the whole research is to develop an effective assessment method - taking all aspects into account - with which the overall evaluation and classification of the surfaces can be done automatically from one sampling. This method will lead to a quantitative, objective and therefore more reliable evaluation of the surface-quality of fair-faced concrete elements.

Open Access: Yes

DOI: DOI not available

Initial value selection of the model parameters in the curve fitting phase of the dynamic SPECT imaging

B. Benyo Péter Somogyi Gábor Hesz K. Kovacs Zsófia Barna Ákos Szlávecz

Publication Name: IFAC Papersonline

Publication Date: 2018-01-01

Volume: 51

Issue: 27

Page Range: 241-246

Description:

The dynamic SPECT (Single Photon Emission Computed Tomography) reconstruction algorithm developed in our prior work reconstructs the parameters of the time activity curve for each image voxel directly from the projection images. In each iterations of the SPECT reconstruction beyond the static 3D MLEM (Maximum Likelihood Expectation Maximization) step, the algorithm performs a fitting process for each voxel in order to estimate the parameters describing the function of the examined organ considering that the time frames are not independent from each other. In real cases the fitted curve is nonlinear function of these parameters, it is usually described as the sum of exponential functions. In order to estimate the parameters properly, an iterative root-finding method is applied. In the current study the Newton-Raphson method is used. The selection of a proper initial value for the root-finding method is critical in order to achieve convergence of the fitting process. If the initial guess is not appropriate, the root-finding algorithm can diverge or converge to an inappropriate parameter set that can result in unacceptable reconstructed parameters. This affects then the subsequent MLEM iterations, also neighboring voxels and breaks the reconstruction. In this work we investigated different methods to calculate the initial values of the fitting process and evaluated the reconstructed parameter set of the dynamic SPECT reconstruction algorithm. Three different methods are investigated, one that uses the fitted parameters of the previous MLEM iteration, one that is based on the sum of the geometrical series of the exponentials and one that calculates the best guess using both methods. The three methods were compared by benchmark reconstruction cases using a mathematical phantom. In each reconstruction different initial value selection method was applied then the time activity curves of the voxels belonging to the same tissue were statistically evaluated using the reconstructed parameters. In the study no significant differences were found in the mean value of the reconstructed parameters. The standard deviation of the parameters was similar between the two simple approaches, however, the combination of the methods resulted in better statistical performance.

Open Access: Yes

DOI: 10.1016/j.ifacol.2018.11.635

On the existence and uniqueness of fixed points of fuzzy cognitive maps

Miklós F. Hatwágner István Harmati L. T. Kóczy

Publication Name: Communications in Computer and Information Science

Publication Date: 2018-01-01

Volume: 853

Issue: Unknown

Page Range: 490-500

Description:

Fuzzy Cognitive Maps (FCMs) are decision support tools, which were introduced to model complex behavioral systems. The final conclusion (output of the system) relies on the assumption that the system reaches an equilibrium point (fixed point) after a certain number of iteration. It is not straightforward that the iteration leads to a fixed point, since limit cycles and chaotic behaviour may also occur. In this article, we give sufficient conditions for the existence and uniqueness of the fixed point for log-sigmoid and hyperbolic tangent FCMs, based on the weighted connections between the concepts and the parameter of the threshold function. Moreover, in a special case, when all of the weights are non-negative, we prove that fixed point always exists, regardless of the parameter of the threshold function.

Open Access: Yes

DOI: 10.1007/978-3-319-91473-2_42

Factors contributing to the enhanced performance of the maxwhere 3D VR platform in the distribution of digital information

Ildiko Horvath Anna Sudar

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2018-01-01

Volume: 15

Issue: 3

Page Range: 149-173

Description:

The rapid evolution of information technology and of a new networked culture in the 21st Century has brought a new question to the forefront of scientific interest: the question of how new technologies influence the effectiveness with which humans are able to perform specific tasks. This paper presents an experiment contrasting traditional 2D interfaces and the MaxWhere 3D VR educational platform in order to shed light on how the effectiveness of various operations and workflows constituting the core of digital literacy has evolved in recent times. In order to draw specific conclusions, a new framework of concepts, qualitative and quantitative metrics and experimental procedures is proposed in the paper. The final goal of the proposed framework is to help evaluate the effectiveness of digital workflows. The results of the experiment, evaluated in terms of the proposed framework, point to the conclusion that when using MaxWhere instead of traditional 2D interfaces, users are able to accomplish the same digital workflows with 30% less user operations, and up to 80% less machine operations. Based on these results, the paper concludes that MaxWhere as an educational platform offers users a number of ways to accomplish tasks that would otherwise require extremely complicated digital workflows in more traditional 2D environments.

Open Access: Yes

DOI: 10.12700/APH.15.3.2018.3.9

The Spiral Discovery Network as an Automated General-Purpose Optimization Tool

Adam B. Csapo

Publication Name: Complexity

Publication Date: 2018-01-01

Volume: 2018

Issue: Unknown

Page Range: Unknown

Description:

The Spiral Discovery Method (SDM) was originally proposed as a cognitive artifact for dealing with black-box models that are dependent on multiple inputs with nonlinear and/or multiplicative interaction effects. Besides directly helping to identify functional patterns in such systems, SDM also simplifies their control through its characteristic spiral structure. In this paper, a neural network-based formulation of SDM is proposed together with a set of automatic update rules that makes it suitable for both semiautomated and automated forms of optimization. The behavior of the generalized SDM model, referred to as the Spiral Discovery Network (SDN), and its applicability to nondifferentiable nonconvex optimization problems are elucidated through simulation. Based on the simulation, the case is made that its applicability would be worth investigating in all areas where the default approach of gradient-based backpropagation is used today.

Open Access: Yes

DOI: 10.1155/2018/1947250

Simulations of higher-order protein organizations using a fuzzy framework

Boldizsar Tuu-Szabo M. Fuxreiter L. T. Kóczy

Publication Name: Complexity

Publication Date: 2018-01-01

Volume: 2018

Issue: Unknown

Page Range: Unknown

Description:

Spatiotemporal regulation of the biochemical information is often linked to supramolecular organizations proteins and nucleic acids, the driving forces of which have yet to be elucidated. Although the critical role of multivalency in phase transition has been recognized, the organization principles of higher-order structures need to be understood. Here, we present a fuzzy mathematical framework to handle the heterogeneity of interactions patterns and the resultant multiplicity of conformational states in protein assemblies. In this model, redundant binding motifs can establish simultaneous and partial interactions with multiple targets. We demonstrate that these multivalent, weak contacts facilitate polymer formation, while recapitulating the observed valency-dependence. In addition, the impact of linker dynamics and motif binding affinity, as well as the interplay between the two effects was studied. Our results support that fuzziness is a critical factor in driving higher-order protein organizations, and this could be used as a general framework to simulate different kinds of supramolecular assemblies.

Open Access: Yes

DOI: 10.1155/2018/6360846

As close as possible to the ungraspable - Somaesthetical and Deleuzian investigations on the Choreographical work of Pál Frenák

Nóra Horváth

Publication Name: Pragmatism Today

Publication Date: 2018-01-01

Volume: 9

Issue: 1

Page Range: 80-90

Description:

According to Shusterman with the notion of somaesthetics he wants to remind the contemporary readers that "philosophy could and should be practiced with one's body rather than being confined to "the life of the mind" (Shusterman 2012, 141.)" Consequently a philosophy can be expressible by one's body especially by a dancer's body or by a choreographer's work. I consider it to be a problem that a performance is not only the artwork of a creator but also the embodiment of the choreographer's philosophy. Not every dance choreographer has his own philosophy but those who have a characteristic "universe" and a peculiar style. I am going to reveal Pál Frenák's dance philosophy of somatic style while searching for that "existential weight" behind his works that is a crucial element in his artistic universe. How is it possible to approach a philosophy emotionally? Where is the limit between sense and sensibility in the reception of a dance performance? Instead of the analysis of concrete meanings of movements in one piece of art, dance philosophy should examine those processes that lead to a certain set of emotions and associations. I feel that conversation on contemporary dance would be a relevant topic in relation to somaesthetics. In my paper, I would like to attune somaesthetics and the Deleuzian sign theory to show the spiritual richness of the oeuvre of Pál Frenák.

Open Access: Yes

DOI: DOI not available

Contact problems in GaAs-based solar cells

Ákos Nemcsics Antal Ürmös Zoltán Farkas László Dobos Szilvia Nagy

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2018-01-01

Volume: 15

Issue: 6

Page Range: 99-124

Description:

The present work deals with contact problems of GaAs-based solar cells. In the introduction the most basic GaAs-based solar cell structures are introduced. Then, the energy and electronic properties are investigated. In the third part of this publication, the technological aspects of the metallization are discussed. Here the surface patterns are investigated, that are formed at the surface of the Au/GaAs and Au/TiN/GaAs material systems, as the effect of the annealing process. The further aim of these investigations to investigate, how the properties of ohmic contact depends on the properties of the material system. If these relations are known, the relationships between different morphologies and their electric qualities will be also known.

Open Access: Yes

DOI: 10.12700/APH.15.6.2018.6.6