Papers by Tomasz Cepowski
Polish Maritime Research, 2001
Napędy i Sterowanie, 2009
Marine Technology Transactions. Technika Morska, 2000
Polish Maritime Research, 2002
Folia Pomeranae Universitatis Technologiae Stetinensis Oeconomica, 2019
In the paper, the author presents the hybrid method of time series modelling using artificial neu... more In the paper, the author presents the hybrid method of time series modelling using artificial neural networks. The illustration of theoretical considerations is the empirical example, in which models and forecasts are determined for microeconomic variable with trend and seasonal fluctuations with high intensity. In the first stage of the research, patterns in time series are identified using the self-organizing Kohonen maps. Next, a modification of the pattern identification method is applied. Based on it, fragments of time series are extracted, then models of multilayer perceptrons are built. In the last stage of the research, forecasts are determined, their quality is assessed on the basis of average ex-post errors. The research confirms the usefulness of hybrid neural models in time series forecasting.
Applied Energy
Estimating container ship fuel consumption using operational parameters. • Clear measurement-base... more Estimating container ship fuel consumption using operational parameters. • Clear measurement-based relationships for fuel consumption. • Impact of fouling, draught, trim, wind, wave and seawater temperature on fuel usage. • Hierarchical impact of operating parameters on ship fuel consumption.
This paper presents the multi-criteria design parameters of the optimisation of the ROPAX ferry u... more This paper presents the multi-criteria design parameters of the optimisation of the ROPAX ferry using sea-keeping characteristics and additional wave resistance. The design criteria were formed using the method based on deterministic scenario and the partial objective functions were determined as artificial neuron networks. The design parameters’ optimisation was carried out with the Pareto method. The best design variants were chosen using the elements of fuzzy logic that allowed, among other things, to present design quality with linguistic variables. This approach allowed choosing the best variant concerning all criteria at the same time.
AddedResistance (MAC/WIN) program was developed for added resistance estimation on head waves by ... more AddedResistance (MAC/WIN) program was developed for added resistance estimation on head waves by the use of an MLP artificial neural network. In order to create a reliable model, only experimental data determined through model tests measurements was used to train this neural network. The following model tests results of these vessels were used in the development of this software: • Van der stel (Gerritsma and Beukelman , 1972; Journee 1976), • S175 containership (Nakamura, 1976), • Series 60 CB=0.6, CB=0.65, CB=0.7, CB=0.75, CB=0.8, Strøm-Tejsen (1973), • WILS II containership (Söding et al., 2014), DTC containership (Sprenger et al. , 2015), • Cruise ship (Ley et al., 2014), Bulk carrier (Kadomatsu, 1988), • RoPax (Sprenger et al., 2015), • KVLCC2 tanker (Guo & Steen, 2010; Sadat-Hosseini et al., 2013), • KRISO containership (Simones et al. 2014). AddedResistance program could have practical application at the preliminary design stage. But this computer program might have two limit...
Polish Maritime Research, 2001
On load tap changing (OLTC) transformer has become a vital link in modern power systems. It acts ... more On load tap changing (OLTC) transformer has become a vital link in modern power systems. It acts to maintain the load bus voltage within its permissible limits despite any load changes. This paper discusses the effect of different static loads namely; constant power (CP), constant current (CI) and constant impedance (CZ) on the maximum power transfer limit from the generation to the load centre through the OLTC branch and in turn on the static stability margin of power systems. Then the paper introduces a novel approach for the on-line determination of the OLTC settings using artificial neural network (ANN) technique in order to improve the power transfer capability of transmission systems. The proposed approach is tested on a sixbus IEEE system. Numerical results show that the setting of OLTC transformer in terms of the load model has a major effect on the maximum power transfer in power systems and the proposed ANN technique is very accurate and reliable. The adaptive settings of OLTC improve the power transfer capability according to the system operating condition.
These files contain the "AddedResistance" computer program binaries, which were develop... more These files contain the "AddedResistance" computer program binaries, which were developed utilising the algorithm presented in the article entitled 'The prediction of ship added resistance at the preliminary design stage by the use of an artificial neural network'. In order to create a reliable model, only experimental data determined through model tests measurements was used to train this neural network. The following model tests results of these vessels were used in the development of this software: • Van der stel (Gerritsma and Beukelman , 1972; Journee 1976), • S175 containership (Nakamura, 1976), • Series 60 CB=0.6, CB=0.65, CB=0.7, CB=0.75, CB=0.8, Strøm-Tejsen (1973), • WILS II containership (Söding et al., 2014), DTC containership (Sprenger et al. , 2015), • Cruise ship (Ley et al., 2014), Bulk carrier (Kadomatsu, 1988), • RoPax (Sprenger et al., 2015), • KVLCC2 tanker (Guo & Steen, 2010; Sadat-Hosseini et al., 2013), • KRISO containership (Simones et al. 2...
AddedResistance (MAC/WIN) program was developed for added resistance estimation on head waves by ... more AddedResistance (MAC/WIN) program was developed for added resistance estimation on head waves by the use of an MLP artificial neural network. In order to create a reliable model, only experimental data determined through model tests measurements was used to train this neural network. The following model tests results of these vessels were used in the development of this software: • Van der stel (Gerritsma and Beukelman , 1972; Journee 1976), • S175 containership (Nakamura, 1976), • Series 60 CB=0.6, CB=0.65, CB=0.7, CB=0.75, CB=0.8, Strøm-Tejsen (1973), • WILS II containership (Söding et al., 2014), DTC containership (Sprenger et al. , 2015), • Cruise ship (Ley et al., 2014), Bulk carrier (Kadomatsu, 1988), • RoPax (Sprenger et al., 2015), • KVLCC2 tanker (Guo & Steen, 2010; Sadat-Hosseini et al., 2013), • KRISO containership (Simones et al. 2014). AddedResistance program could have practical application at the preliminary design stage. But this computer program might have two limit...
The naval architect has to tackle many of the problems, while designing ships for the loading, st... more The naval architect has to tackle many of the problems, while designing ships for the loading, storage and transport of polymetallic or other nodules, this article focuses on how to assure appropriate hull strength. This author proposes mathematical relationships and operational and design solutions allowing to more effectively reduce shear forces and bending moments during the loading of nodules in the open sea. The suggested solutions may be used in the design of ships intended for such or other functions.
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Papers by Tomasz Cepowski