Publications in journals ranked by Journal Citation Reports (JCR) 
Publications in other journals ranked by Ministry of Science and Higher Education
Conference publications indexed in the Web of Science Core Collection
Publications in other journals and conference proceedings
Affiliation to IPPT PAN

1.Marszałek A., Burczyński T., Ordered Fuzzy GARCH Model for Volatility Forecasting, Includes the proceedings of the 10th Conference of the European Society for Fuzzy Logic and Technology (EUSFLAT-2017), 2017-09-11/09-15, Warszawa (PL), No.XI, pp.480-492, 2018
Marszałek A., Burczyński T., Ordered Fuzzy GARCH Model for Volatility Forecasting, Includes the proceedings of the 10th Conference of the European Society for Fuzzy Logic and Technology (EUSFLAT-2017), 2017-09-11/09-15, Warszawa (PL), No.XI, pp.480-492, 2018

Abstract:
A volatility forecasting comparative study between the most popular original GARCH model and the same model defined based on concepts of Ordered Fuzzy Numbers and Ordered Fuzzy Candlsticks is presented. These approaches offer a suitable tool to handle both imprecision of measurements and uncertainty associated with financial data. Therefore, they are particularly useful for volatility forecasting, since the volatility is unobservable and a proxy for it is used (realised volatility). In presented study, based on intra-daily data of theWarsaw Stock Exchange Top 20 Index (WIG 20), one showed that based on the adjusted-R squared and several prediction measurements, the fuzzy approach does perform better than the original GARCH model and forecasts more precisely in both the in-sample and out-of-sample predictions

Keywords:
Volatility forecasting, Realized volatility, Ordered fuzzy number, Kosinski’s fuzzy number, Ordered fuzzy candlestick, Ordered fuzzy GARCH model, Financial high-frequency data

2.Wiśniewski K., Turska E., Recent improvements to nine-node shell element MITC9 with drilling rotations, SSTA 2017, Shell Structures: Theory and Applications, 2017-10-11/10-13, Gdańsk (PL), Vol.4, pp.399-402, 2018
Wiśniewski K., Turska E., Recent improvements to nine-node shell element MITC9 with drilling rotations, SSTA 2017, Shell Structures: Theory and Applications, 2017-10-11/10-13, Gdańsk (PL), Vol.4, pp.399-402, 2018

Abstract:
The paper describes our improved 9-node quadrilateral shell element MITC9i, which is derived for the Reissner-Mindlin shell kinematics, the extended potential energy functional and Green strain.
1. The MITCi technique is used to avoid locking and it is based on the improved transformations proposed in (Wisniewski & Panasz 2013) for a membrane element. Here, these transformations are extended to bending/twisting and transverse shear shell strains.
2. To reduce the shape distortion effects, the so-called corrected shape functions (CSF) of (Celia & Gray 1984) are used instead of the isoparametric ones, and we propose the method of computation the shift parameters for non-flat shell elements.
3. The drilling rotations are included via the drilling Rotation Constraint and the penalty method. This rotation is used in the multiplicative/additive update scheme valid for large (unrestricted) rotations.
The effect of the MITC9i technique and the CSF is that all three patch tests are passed, also for shifted side nodes along the straight edges and for arbitrary shifts of an interior node. The MITC9i shell element was subjected to a range of linear and non-linear numerical tests described in (Wisniewski & Turska 2017); here we provide additional examples illustrating its accurate and robust behavior.

Keywords:
9-node shell element MITC9,two-level approximation of strains, corrected shape functions, node shift parameters, drilling rotations

3.Rojek J., Zubelewicz A., Madan N., Nosewicz S., New formulation of the discrete element method, AIP Conference Proceedings, ISSN: 0094-243X, Vol.1922, No.030009, pp.1-8, 2018
4.Wawrzyk K., Kowalczyk P., Nosewicz S., Rojek J., A constitutive model and numerical simulation of sintering processes at macroscopic level, AIP Conference Proceedings, ISSN: 0094-243X, Vol.1922, No.030011, pp.1-7, 2018
5.Nowak Z., Nowak M., Widłaszewski J., Kurp P., Experimental and Numerical Investigation on Laser-Assisted Bending of Pre-Loaded Metal Plate, AIP Conference Proceedings, ISSN: 0094-243X, DOI: 10.1063/1.5019148, Vol.1922, pp.140006-1-7, 2018
Nowak Z., Nowak M., Widłaszewski J., Kurp P., Experimental and Numerical Investigation on Laser-Assisted Bending of Pre-Loaded Metal Plate, AIP Conference Proceedings, ISSN: 0094-243X, DOI: 10.1063/1.5019148, Vol.1922, pp.140006-1-7, 2018

Abstract:
The laser forming technique has an important disadvantage, which is the limitation of plastic deformation generated by a single laser beam pass. To increase the plastic deformation it is possible to apply external forces in the laser forming process. In this paper, we investigate the influence of external pre-loads on the laser bending of steel plate. The pre-loads investigated generate bending towards the laser beam. The thermal, elastic-plastic analysis is performed using the commercial nonlinear finite element analysis package ABAQUS. The focus of the paper is to identify how this pattern of the pre-load influence the final bend angle of the plate

Keywords:
Laser forming, Force-assisted laser forming, Laser-assisted bending, Thermo-mechanical simulations, Finite element analysis

6.Ranachowski Z., Schabowicz K., Gorzelańczyk T., Kudela Jr S., Dvorak T., Visualization of Fibers and Voids Inside Industrial Fiber Concrete Boards, Material Science & Engineering International Journal, ISSN: 2574-9927, DOI: 10.15406/mseij.2017.01.00022, Vol.1, No.4, pp.1-4, 2018
Ranachowski Z., Schabowicz K., Gorzelańczyk T., Kudela Jr S., Dvorak T., Visualization of Fibers and Voids Inside Industrial Fiber Concrete Boards, Material Science & Engineering International Journal, ISSN: 2574-9927, DOI: 10.15406/mseij.2017.01.00022, Vol.1, No.4, pp.1-4, 2018

Abstract:
Fiber cement boards (FCB) microstructure and methods of fabrication are described. The method of X-ray microtomography in application for investigating of FCB microstructure is presented. The cellulose fibers constituting the remarkable reinforcement of the FCB are colorless and too small to be seen applying the standard optical methods. The X-ray microtomography method however enabled the authors to realize three goals within the investigation of the properties of FCB. The length and shape of the fibers could be assessed on specimens’ cross-sections. Applying the pseudo 3D visualization it was possible to visualize the cracked regions inside the specimen volume. The case of non-uniform fibers distribution in respect to the board thickness which was impossible to recognize applying the standard visual inspection, was also performed by merging the multiple cross-section images into a single graph