Journal articles (JCR) by Rafal Michalski
Success Factors in Sustainable Management of IT Service Projects, 2021
Management of successful IT projects in a sustainable manner is influenced by numerous factors. O... more Management of successful IT projects in a sustainable manner is influenced by numerous factors. Organizational awareness of the necessity of engaging all project stakeholders is an important is-sue that helps in meeting project sustainable development goals. While there are many studies on the success factors of IT software projects, there is still little coherent research on the success fac-tors of IT service projects. The purpose of this article is to contribute in filling this gap by attempt-ing to identify success factors of the IT services project involving both traditional and agile ap-proaches and considering sustainable development, specifically in terms of the stakeholders’ role in project management. We conducted questionnaire-based research involving 155 IT service pro-ject managers. The results of the study were subjected to exploratory factor analysis. As a result, we presented and thoroughly formally examined the factorial model of success components in the IT service industry. We distinguished four factors: (1) agile techniques and change management, (2) organization and people, (3) stakeholders and risk analysis, and (4) work environment. The results were compared with analogous studies found in the literature. The research showed that both traditional and agile management approaches coexist, meet sustainable development goals, and are significant for the successful management in IT service projects where all stakeholders play an important role.
Preventing Work-Related Musculoskeletal Disorders, 2020
This research concerns the workplace design methodology, involving digital human models, that pre... more This research concerns the workplace design methodology, involving digital human models, that prevents work-related musculoskeletal disorders (WMSDs). We propose an approach that, in conjunction with one of the classic WMSD risk assessment methods, allows one to simplify simulations in a three-dimensional digital environment. Two real-life workstations from a manufacturing industry were modelled in a 3D Studio Max environment by means of an Anthropos ErgoMax system. A number of simulations show that, for the examined cases, classic boundary mannequins' approaches can be replaced by using 50th percentile of a population individual, with a minimal impact on the WMSD risk. Although, the finding might not be suitable in all situations, it should be considered, especially where compromise solutions are being sought due to other criteria.
Modeling human thinking about similarities by neuromatrices in the perspective of fuzzy logic , 2020
In this work, we propose a new method for modeling human reasoning about objects' similarities. W... more In this work, we propose a new method for modeling human reasoning about objects' similarities. We assume that similarity depends on perceived intensities of objects' attributes expressed by natural language expressions such as low, medium, and high. We show how to find the underlying structure of the matrix with intensities of objects' similarities in the factor-analysis-like manner. The demonstrated approach is based on fuzzy logic and set theory principles, and it uses only maximum and minimum operators. Similarly to classic eigenvector decomposition, we aim at representing the initial linguistic ordinal-scale (LOS) matrix as a max-min product of other LOS matrix and its transpose. We call this reconstructing matrix a neuromatrix because we assume that such a process takes place at the neural level in our brain. We show and discuss on simple, illustrative examples, how the presented way of modeling grasps natural way of reasoning about similarities. The unique characteristics of our approach are treating smaller attribute intensities as less important in making decisions about similarities. This feature is consistent with how the human brain is functioning at a biological level. A neuron fires and passes information further only if input signals are strong enough. The proposal of the heuristic algorithm for finding the decomposition in practice is also introduced and applied to exemplary data from classic psychological studies on perceived similarities between colors and between nations. Finally, we perform a series of simulation experiments showing the effectiveness of the proposed heuristic.
Central European Journal of Operations Research, 2020
Two simulation experiments were conducted to verify whether the idea of virtual force scatter plo... more Two simulation experiments were conducted to verify whether the idea of virtual force scatter plot algorithm, used for searching solutions of the facility layout problems, may be used as an input to the classical CRAFT and simulated annealing (SA) algorithms. The proposed approach employs a regular grid for specifying possible locations of objects. Three independent variables were investigated in the first experiment, namely, (1) the size of the problem: 16, 36 and 64 objects, (2) the type of links between objects: grid, line, and loop, and (3) the shape of the possible places in which the objects can be situated: circle, row and square. The patterns of possible location places were also adapted to the analysis of examples taken from literature, included in the second experiment. The gathered data were statistically analyzed. The results shows substantial decrease in goal function means for all of the examined experimental conditions, if the proposed starting solutions are applied to the CRAFT algorithm. The application of the approach to SA is profitable in specific tasks. The presented comparative numerical results show, in which circumstances the proposed method is superior over various genetic algorithms and other hybrid approaches. Overall, the experimental data investigation demonstrates the usefulness of the proposed method and encourages further research in this direction.
Visual inspection is used in many areas due to the potential high costs of inspection error such ... more Visual inspection is used in many areas due to the potential high costs of inspection error such as injury, fatality, loss of expensive equipment, scrapped items, rework, or failure to procure repeat business. This study presents an application of hidden Markov models (HMM) to fixations' sequences analysis during visual inspection of front panels in a home appliance facility. The eye tracking data are gathered when quality control operators perform their tasks. The results support the difference between expert and novice operator. Moreover, the article demonstrates four HMMs with two and three hidden states both for novice and experienced operators and provides analysis and discussion of the outcomes.
The research demonstrates the use of hidden Markov models (HMMs) in analyzing fixation data recor... more The research demonstrates the use of hidden Markov models (HMMs) in analyzing fixation data recorded by an eye-tracker. The visual activity was registered while performing pairwise comparisons of simple marketing messages. The marketing information was presented in a form of digital leaflets appearing on a computer screen and differed in the components' arrangement and graphical layout. Better variants were selected by clicking on them with a mouse. A simulation experiment was performed to determine best HMMs in terms of information criteria. Seven selected models were presented in detail, four of them graphically illustrated and thoroughly analyzed. The identified hidden states along with predicted transition and emission probabilities allowed for the description of possible subjects' visual behavior. Hypotheses about relations between these strategies and marketing message design factors were also put forward and discussed.
Various designs of typical digital control panels were analyzed experimentally from both the effe... more Various designs of typical digital control panels were analyzed experimentally from both the effectiveness and efficiency points of view. Subjects performed information comparison tasks aimed at keeping vehicle velocity at the same level. The experiment involved two versions of speedometers for displaying current and target velocities (clock-face and digital). The stimuli were also differentiated by the target velocity value (20, 50 and 80 km/h) and the correct response type (increase or decrease). Subjects' performance results along with the eye-tracking data were qualitatively and quantitatively analyzed for all 24 experimental conditions.
The paper presents a novel version of the simulated annealing algorithm based on linguistic patte... more The paper presents a novel version of the simulated annealing algorithm based on linguistic patterns (LP) and fuzzy theory approach. The article describes shortly the linguistic patterns and shows on a simple illustrative example the idea of using the Łukasiewicz formula as a criterion for the facility layout optimization. Next, the detailed description of our LP version of simulated annealing is presented. The influence of the proposed algorithm parameters on the effectiveness of our approach is then examined in a simulation experiment involving four different types of facility layout problems. The outcomes from the first experiments are used for optimally setting the parameters of our proposal in the second simulation study focused on verifying its effectiveness for objects with uniform and variable sizes. The obtained results show that the presented procedure, apart from producing decent results in terms of the classic goal function and the linguistic pattern criterion, provided solutions that were qualitatively different than those generated by a crisp version.
Computers in Human Behavior, 2015
Preferences toward graphical variants of smartphone’s packages are examined.Right located brand n... more Preferences toward graphical variants of smartphone’s packages are examined.Right located brand name is better rated than the left one.Big and compact text version more preferred than the smaller and dispersed one.Males dislike pink background color and consider it as the most important factor.Females like pink, but the background color has low impact on their preferences.The main goal of this research was the analysis of persons’ attitudes toward digital graphical information regarding various types of smartphone’s virtual package designs. Sixty students from two different faculties were involved in the study. Both the faculty and gender effects were controlled. The packages were electronically presented to the subjects on the computer screen. A binary pairwise procedure within the framework of the conjoint analysis was employed to assess the examinees’ preferences. The experimental stimuli differed in the brand name location in relation to the product image (left and right hand side), background colors used (grey and pink), and the typography applied to the brand name (big and compact text versus small with the increased interletter spacing). The main results showed significant effects of brand name location and typography along with significant interactions concerned with the background package color. Generally, males preferred grey variants while females – pink. These results analyzed along with the conjoint analysis outcomes surprisingly show that the background color was the main factor influencing males’ preferences while for women it was the least important issue. The cluster analysis results demonstrated significant interpersonal discrepancies and identified three, similar in number, groups sharing common preference structures.
Color grouping in visual search behavior, 2014
The article investigates how the various colors and color pairs used as grouping factors affect t... more The article investigates how the various colors and color pairs used as grouping factors affect the visual search process and direct manipulation activities in the context of toolbar-like graphical panels. Red, green, and blue colors having the same perceptual distance in the CIELab space are used. The results demonstrate significant influence of the examined color-related factors on the speed and accuracy. The color preattentive property depends strongly on the grouping pattern: layouts with smaller colored areas were operated worse than panels divided into larger parts. Meaningful differences were also observed between panels with single and two colored backgrounds.
Preferences were examined by pairwise comparisons before and after performing the 'search and select' tasks. Subjective judgments were significantly differentiated by the toolbar background color pattern both prior to the performance tasks and after them. The initial relative weights structure changed decidedly after the performance experience being more consistent with the 'search and select' results. The location factor was irrelevant for the speed and accuracy as well as for preferences. Objective and subjective findings are compared and discussed. Linear regression models showing the preference structure change and the relationship between mean acquisition times and mean preference weights are developed and discussed.
IEEE computer graphics and applications
Researchers employed digital manikins to determine the space necessary in an emergency-medical-se... more Researchers employed digital manikins to determine the space necessary in an emergency-medical-service helicopter to effectively and efficiently conduct life-saving medical procedures. To simulate resuscitation with appropriate digital human models, they used Anthropos ErgoMAX modeling software in the 3D Studio Max environment.
The main purpose of this study was to investigate the nature of preferences and their relation to... more The main purpose of this study was to investigate the nature of preferences and their relation to the objective measures in simple direct manipulation tasks involving both the cognitive process as well as the visually guided pointing activities. The conducted experiment was concerned with the graphical structures resembling toolbars widely used in graphical interfaces. The influence of the graphical panel location, panel configuration as well as the target size on the user task efficiency and subjects' preferences were examined. The participants were requested to express their attitudes towards the tested panels before and after the efficiency examination. This subjective evaluation was carried out within the framework of Analytic Hierarchy Process (AHP; Saaty, 1977; 1980). The subjective results that were obtained showed significant differences in the subjects' preferences towards examined panels before and after completing the tasks. It seems that the users are able to comparatively quickly change their minds after gaining some experience with the investigated stimuli. Additionally, the applied cluster analysis revealed that the subjects were not homogenous in their opinions, and they formed groups having similar preference structures.
The paper is concerned with various ways of analysing the subjective assessment of displaying dig... more The paper is concerned with various ways of analysing the subjective assessment of displaying digital signage con-tent. In the beginning the brief description of the signage system evolution is described and next, the carried out ex-periment is depicted. The preferences of the 32 subjects were obtained using pairwise comparisons of the designed screen formats. Then the priorities were derived by applying the Analytic Hierarchy Process (Saaty, 1977; 1980) framework. The gathered data were modelled and analysed by means of the analysis of variance, multiple regression, conjoint and factor analysis. The results suggest that the application of different methods of preference analysis may provide additional information, which could facilitate more in-depth understanding of the given preference structure.
In this paper, results of experimental research on the preattentive mechanism in the human-comput... more In this paper, results of experimental research on the preattentive mechanism in the human-computer interaction (HCI) were presented. Fifty four subjects were asked to find interface elements from various panel structures. The arrangements were differentiated by their orientation (vertical, horizontal), colour pattern (ordered, unordered) and object background colours (green-blue, green-red, blue-red). The main finding of the study generally confirms the profits provided by the visual preattentive processing of the colour feature in graphical panel operation efficiency. However, the vertical way of arranging the items in search layouts resulted in decreasing the preattentive effect related to the item background colour. In regular, chessboard-like patterns of different coloured items, the effect of the early vision was less salient than in the case of structures with randomly dispersed colours. The reported results can help in designing efficient graphical user-computer interfaces in many interactive information systems.
The main objective of this paper was to investigate the effects of a computer screen interface de... more The main objective of this paper was to investigate the effects of a computer screen interface design and its related geometrical characteristics of 36 graphical objects on a user's task efficiency. A total of 490 subjects took part in laboratory experiments that focused on the direct manipulation of a visual dialogue between a user and a computer. The subjects were asked to select an object from among a group of items randomly placed on the computer screen that were visible exclusively during the visual search process. A model expressing the mean object acquisition time as a function of graphical object size and the configuration was developed and statistically validated. The model showed an influence of geometrical design characteristics of the graphical objects (icons) and their groupings (icon structures) on the observed task efficiency. The reported results can be used at those stages of a software lifecycle that concentrate on prototyping, designing, and implementing graphical solutions for the efficient graphical user-computer interface.
Conference articles (Scopus, Web of Science) by Rafal Michalski
Information on how to present visual content in an ergonomic way is crucial in various fields. Th... more Information on how to present visual content in an ergonomic way is crucial in various fields. The current study examines how the gender, race of a person, and picture-slogan relative location influence subjects' perceived effectiveness about a social advertisement. Relative scores of 45 participants from Wrocław University of Science and Technology were measured by binary pairwise comparisons and formally analyzed by the loglinear model for frequency data. While making comparisons, subjects' visual activity was recorded by an eye-tracking system. Mean fixation durations were comprehensively analyzed in the context of examined factors by a standard, five-way analysis of variance: Picture race (black, yellow, white) Â Picture gender (man, woman) Â Picture location (left, right) Â Stimulus location (left, right) Â Subject gender (male, female). Subjective results regarding perceived effectiveness of the advertisement variants were compared with objective fixation durations.
The main goal of this research is to examine the influence of various control panel background co... more The main goal of this research is to examine the influence of various control panel background colors and geometrical layouts on users' subjective perceptions. We investigated five different colors including red, green, blue, white and grey as well as two different arrangements of the panel's informative and controlling items. In the latter case, more vertical and more horizontal layouts were investigated. Panels included typical elements and colors were selected in such a way that their perceptual differences in the CIE Lab color space are similar. A method involving pairwise comparisons was applied to compute relative preferences towards examined conditions. The outcomes generally showed significant influence of the studied effects on the subjects' subjective assessments.
Journal articles (not JCR) by Rafal Michalski
Operations Research and Decisions, 2008
W pracy przedstawiono przegląd podejść do zapewniania jakości użytkowej systemów informatycznych.... more W pracy przedstawiono przegląd podejść do zapewniania jakości użytkowej systemów informatycznych. Zaprezentowano historyczny rozwój modeli wytwarzania oprogramowania. Wyróżniono dwie grupy: klasyczną, wywodzącą się z inżynierii oprogramowania oraz zorientowaną na końcowego użytkownika. Przedstawiono różne typologie metod oceny oprogramowania oraz nakreślono aktualne problemy i potencjalne kierunki badań dotyczących przyjaznych systemów informatycznych.
In the paper Subjective Overall Workload Assessment (SOWA) method was proposed and described. A c... more In the paper Subjective Overall Workload Assessment (SOWA) method was proposed and described. A computer information system supporting the process of generating appropriate assessment questionnaires and speeding up the analysis of collected data was presented. Next, the SOWA was practically applied for assessing the subjective workload of persons employed in a Polish sport textile industry company. The obtained results from 18 employees were presented and analysed. Finally, possible advantages, disadvantages, limitations, future works, and a range of applications of the SOWA were discussed.
Uploads
Journal articles (JCR) by Rafal Michalski
Preferences were examined by pairwise comparisons before and after performing the 'search and select' tasks. Subjective judgments were significantly differentiated by the toolbar background color pattern both prior to the performance tasks and after them. The initial relative weights structure changed decidedly after the performance experience being more consistent with the 'search and select' results. The location factor was irrelevant for the speed and accuracy as well as for preferences. Objective and subjective findings are compared and discussed. Linear regression models showing the preference structure change and the relationship between mean acquisition times and mean preference weights are developed and discussed.
Conference articles (Scopus, Web of Science) by Rafal Michalski
Journal articles (not JCR) by Rafal Michalski
Preferences were examined by pairwise comparisons before and after performing the 'search and select' tasks. Subjective judgments were significantly differentiated by the toolbar background color pattern both prior to the performance tasks and after them. The initial relative weights structure changed decidedly after the performance experience being more consistent with the 'search and select' results. The location factor was irrelevant for the speed and accuracy as well as for preferences. Objective and subjective findings are compared and discussed. Linear regression models showing the preference structure change and the relationship between mean acquisition times and mean preference weights are developed and discussed.