Adam Sadowski, Piotr Wojciechowski and Per Engelseth
In a volatile marketplace, warehouse management is fundamentally contingent of changes in its supply network environment. Flexibility is therefore a key logistics issue in…
Abstract
Purpose
In a volatile marketplace, warehouse management is fundamentally contingent of changes in its supply network environment. Flexibility is therefore a key logistics issue in distribution centre management. This study probes into the nature of warehouse flexibility in a supply network through simulation.
Design/methodology/approach
By using the FlexSim simulation tool the dynamic behaviour of the warehouse system are conceptualised, documented, simulated, analysed and evaluated.
Findings
Simulation revealed that external changes affect daily processes and the reorganisation of warehouse processes. Given the extensity of resource use, simulation also revealed that process reorganisation should not be a daily undertaking. This is because warehouse processes react in unpredictable and different manners to even the smallest disturbance from the environment. This reaction is not necessarily negative impending more long-term change of warehouse processes.
Originality/value
The warehouse is a complex system that self-adapts with limited need to calculate new optimised warehouse processes to counter changes in its environment. Rather than following deterministic optimisation procedures, the development of flexible resources is a key issue in warehouse management. The applied simulation model is generic and therefore applicable in other distribution centres pointing to how to monitor warehouse processes to in a pre-emptively develop warehouse flexibility through change of process context.
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Rafal M. Wojciechowski, Cezary Jedryczka, Piotr Lukaszewicz and Dariusz Kapelski
The purpose of this paper is to investigate application possibilities of soft magnetic composites (SMC) in the design of high speed permanent motors for home appliances.
Abstract
Purpose
The purpose of this paper is to investigate application possibilities of soft magnetic composites (SMC) in the design of high speed permanent motors for home appliances.
Design/methodology/approach
The design of high speed permanent magnet motor (HSPM) with core made of SMC has been proposed. The governing information about SMC has been presented. The possible advantages and disadvantages of applying magnetic powder materials in the design of electrical machines have been studied. To solve the partial differential equations describing magnetic vector distribution in considered HSPM, the edge element method (EEM) has been applied. The formulas of permanent magnet and winding descriptions, and electromagnetic torque calculations have been presented and studied. To verify accuracy of methodology and functionality of the elaborated software, a prototype of the considered motor has been built and the experimental setup for testing torque and electromotive force has been elaborated. The comparison between measured and simulated motor characteristics have been presented and discussed.
Findings
Comparison between measured and simulated motor characteristics proves the model accuracy. The obtained results show that the designed HSPM motor has sinusoidal electromotive force waveforms, low cogging torque value and the sinusoidal torque versus rotor angle characteristics. Moreover, it has been indicated that the application of SMC materials can reduce power losses in the high speed motors.
Originality/value
The paper describes the development of the numerical method and software for analysis of HSPM with core made of powder materials.
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Dominik Szajerman, Piotr Napieralski and Jean-Philippe Lecointe
Technological innovation has made it possible to review how a film cues particular reactions on the part of the viewers. The purpose of this paper is to capture and interpret…
Abstract
Purpose
Technological innovation has made it possible to review how a film cues particular reactions on the part of the viewers. The purpose of this paper is to capture and interpret visual perception and attention by the simultaneous use of eye tracking and electroencephalography (EEG) technologies.
Design/methodology/approach
The authors have developed a method for joint analysis of EEG and eye tracking. To achieve this goal, an algorithm was implemented to capture and interpret visual perception and attention by the simultaneous use of eye tracking and EEG technologies. All parameters have been measured as a function of the relationship between the tested signals, which, in turn, allowed for a more accurate validation of hypotheses by appropriately selected calculations.
Findings
The results of this study revealed a coherence between EEG and eye tracking that are of particular relevance for human perception.
Practical implications
This paper endeavors both to capture and interpret visual perception and attention by the simultaneous use of eye tracking and EEG technologies. Eye tracking provides a powerful real-time measure of viewer region of interest. EEG technologies provides data regarding the viewer’s emotional states while watching the movie.
Originality/value
The approach in this paper is distinct from similar studies because it takes into account the integration of the eye tracking and EEG technologies. This paper provides a method for determining a fully functional video introspection system.
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Michał R. Nowicki, Dominik Belter, Aleksander Kostusiak, Petr Cížek, Jan Faigl and Piotr Skrzypczyński
This paper aims to evaluate four different simultaneous localization and mapping (SLAM) systems in the context of localization of multi-legged walking robots equipped with compact…
Abstract
Purpose
This paper aims to evaluate four different simultaneous localization and mapping (SLAM) systems in the context of localization of multi-legged walking robots equipped with compact RGB-D sensors. This paper identifies problems related to in-motion data acquisition in a legged robot and evaluates the particular building blocks and concepts applied in contemporary SLAM systems against these problems. The SLAM systems are evaluated on two independent experimental set-ups, applying a well-established methodology and performance metrics.
Design/methodology/approach
Four feature-based SLAM architectures are evaluated with respect to their suitability for localization of multi-legged walking robots. The evaluation methodology is based on the computation of the absolute trajectory error (ATE) and relative pose error (RPE), which are performance metrics well-established in the robotics community. Four sequences of RGB-D frames acquired in two independent experiments using two different six-legged walking robots are used in the evaluation process.
Findings
The experiments revealed that the predominant problem characteristics of the legged robots as platforms for SLAM are the abrupt and unpredictable sensor motions, as well as oscillations and vibrations, which corrupt the images captured in-motion. The tested adaptive gait allowed the evaluated SLAM systems to reconstruct proper trajectories. The bundle adjustment-based SLAM systems produced best results, thanks to the use of a map, which enables to establish a large number of constraints for the estimated trajectory.
Research limitations/implications
The evaluation was performed using indoor mockups of terrain. Experiments in more natural and challenging environments are envisioned as part of future research.
Practical implications
The lack of accurate self-localization methods is considered as one of the most important limitations of walking robots. Thus, the evaluation of the state-of-the-art SLAM methods on legged platforms may be useful for all researchers working on walking robots’ autonomy and their use in various applications, such as search, security, agriculture and mining.
Originality/value
The main contribution lies in the integration of the state-of-the-art SLAM methods on walking robots and their thorough experimental evaluation using a well-established methodology. Moreover, a SLAM system designed especially for RGB-D sensors and real-world applications is presented in details.
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In the second half of the 1980s, together with Perestroika in the Soviet Union, a process took place to end the Cold War as a confrontation between the United States of America…
Abstract
In the second half of the 1980s, together with Perestroika in the Soviet Union, a process took place to end the Cold War as a confrontation between the United States of America and the Soviet Union. At the same time, this process caused the collapse of the Soviet Union and socialist system and thereafter the separation and independence of the many nationalities that constituted the Soviet socialist system in the East and South Europe. However to our regret, such nationalities could not enjoy freedom by independence, but went to brutal wars between separated nationalities. Even after many local wars and brutalities we cannot yet find the final solution through peace and justice for peoples.