Zsolt Tibor Kosztyán

Navigation methods of special needs users in multimedia systems

In todays information society, computer users frequently need to seek for information on home pages as well as to select among software functions. A well-designed interface is essential in order to find everything necessary and meet the requirements of both the average user and users with special needs. Proper placement of objects on the screen is important to decrease perception time. One of the well-known researchers of web ergonomics, Jakob Nielsen (2006) established in an eye-tracking experiment that users scan displayed homepages in an F shape. In the present project the task was to find similar shapes in a number of playful visual search games. Several multimedia tasks were developed for this investigation. Our experiments included normal users and users with intellectual disabilities. We tested whether the characteristic searching routes and navigation methods differed between normal users and those with intellectual disabilities. The results of this investigation can inform the design and position of graphical user interface elements.

Stochastic Network Planning Method

The success of the realisation of a project depends greatly on the efficiency of the planning phase. This study presents a new technology supporting the planning phase.

Matrix-based color measurement corrections of tristimulus colorimeters.

For colorimetric imaging the tristimulus technique is still the best practical method to keep the measurement time within reasonable limits. However, the achievable color measurement uncertainties for special sources can be large. It is described how the systematic errors can be significantly reduced by using matrix-based color corrections and how the matrix elements can be optimized to obtain the smallest spectral mismatch errors for different light-source distributions. An approach for decreasing the systematic errors is to increase the number of the colorimeter channels (or filters) used for a measurement. Using five channels in a colorimeter is an optimum choice. Determination of the optimum matrices for the five channels is discussed. The correction matrices are designed such that the spectral mismatch errors of the realized functions are minimized relative to the CIE standard color matching functions for several selected test-source distributions. The optimum matrix depends on the (test) light source to be measured. Adaptive matrix values are determined by using the channel outputs and the spectral power distribution of color LEDs approximated with a simple approximation function. The systematic errors are evaluated for a number of colored and white LEDs. The noise propagation with the applied matrix corrections is investigated.

Exact algorithm for matrix-based project planning problems

A novel PDM matrix is proposed to model agile software development projects.A novel EPR algorithm proposed to specify the best n probable project scenarios.The proposed EPR algorithm specifies the best n feasible project structures.The EPR determines how to restructure a project plan if management claims change. This paper proposes a new matrix-based project planning method that takes into consideration task importance or probability of completions thus determines and ranks the importance or probability of possible project scenarios and project structures. The proposed algorithm is fast, aims to select the most important project scenarios or the least cost/time demanding project structures. The algorithm is generic, can host several types of goals dictated by the characteristics of project management and as such can be the fundamental element of a project expert- and decision-making system.

Analysing the 2D, 3D and Web User Interface Navigation Structures of Normal Users and Users with Mild Intellectual Disabilities

Design questions of home pages are examined by numerous visual search experiments as well. However, in the majority of experiments only one target object has to be searched. On web pages and on 2D and 3D scenes often more objects, more information have to be discovered. Spatial placement of objects has influential role on reaction times, how soon an object will be found. In our work more objects had to be found on home pages and on skill-improving game programs by normal users and users with mild intellectual disabilities. We investigated the time and the sequence of finding targets in function of their location on the screen and their properties (e.g. size). We worked out a method for analysing navigation routes and discovering differences between the target groups, which can be used in further investigations as well.

Risk-based multivariate control chart

A new Risk-Based control chart is designed that minimizes the number of type II error.This chart can handle multivariate case and takes the measurement uncertainty into account.The total cost of decision can be decreased applying the RBT2 chart. Control charts are widely used tools in statistical process control (SPC). Most of the control charts operates on reliability base, so the users assume that the value of the real product characteristic is equal to the value derived from the measurement. It is a frequent case that the conformity of a product is determined by more than one product characteristics. It is recommended to apply multivariate control charts for the control of multiple product characteristics, but the measurement uncertainty can lead to incorrect decisions even in univariate case. In this study, the authors develop a risk-based multi-dimensional T2 chart (RBT2), which takes the consequences of the decisions into account and reduces the risks during the process control. The proposed method can be applied even for non-normally distributed data. Several sensitivity analyses are provided and the performance of the RBT2 chart is demonstrated when Six Sigma regulations are fulfilled.

Using Multimedia Interactive E-teaching in Color Science

Abstract Color is becoming a key issue in many e-commerce products. This made it necessary to develop a color course easily accessible from the Internet or distributed on CD-ROM. This article describes the advantages of the electronic approach – compared to class-room demonstrations – to bring the fundamentals of colorimetry to the student with the help of demonstrations.

Navigation Strategies in Case of Different Kind of User Interfaces

Information seeking is a very frequent task in our everyday computer usage. We often search not only one but also more information, more objects on web pages, on the user interface of different kind of software or multimedia program. In our study we sought the answer to the question how property of objects (etc. size, form) influence the time needed to find them, how object placement influence searching time, what kind of searching strategy users use to find the targets and whether we find everything we need. We examined within-page navigation thus, all targets were placed on the same screen. Users had to search among 2and 3-dimensional shapes and in pictures.

Unbiased one-dimensional university ranking – application-based preference ordering

Our main goal is to produce a ranking technique which overcomes shortcomings of the numerous university rankings published. We propose a ranking method that provides a one-dimensional preference list of universities which is solely based on the partial rankings of applicants. Our ranking is free of subjective weights and uncomparable dimensions.

Matrix-Based Methods for Supporting Logic Planning of IT Projects

In case of using methodology of project planning, in the first step we had to create a “good” logic network. We had to determine the successors and predecessors of the tasks. However, usually successors and predecessors proceed from the technology, sometimes (especially in case of IT and innovation projects) these relations between tasks are not explicit. In case of projects especially IT and innovation projects; one of the most critical points of views is the phase of logic planning. In spite of the fact that it is a very important phase, it is hardly supported by any kind of project management tools. Our goal was to support the logic planning phase. In our study a new planning method, namely Project Expert Matrix (PEM) is introduced. The PEM method can determine all feasible solutions with the help of stochastic variables and can also take into consideration all the possible precedents. The parameters of logic relations can be changed if the impacts on the project change. With this method the most probable project scenario can be determined taking into account time, cost, and resource demands.