Andrzej Romanowski

ECT Image Analysis Methods for Shear Zone Measurements during Silo Discharging Process

Abstract The paper covers the electrical capacitance tomography (ECT) data analysis on shear zones formed during silo discharging process. This is due to the ECT aptitude for detection of slight changes of material concentration. On the basis of ECT visualisations, wall-adjacent shear zone profiles are analysed for different wall roughness parameters. The analysis on changes of material concentration, based on ECT images, enables the calculation for the characteristic parameters of shear zones—size and material concentration inside the shear zone in a dynamic process of silo discharging. In order to verify the methodology a series of experiments on gravitational flow of bulk solids under various conditions were conducted with different initial granular material packing densities and silo wall roughness. The investigation shows that the increase in container wall roughness is an effective method for reducing the dynamic effects during the material discharging, since these effects are resulted from the resonance between hopper construction and trembling material. Such effects will damage industrial equipment in practical applications and need further investigation.

Everyday problems vs. UbiComp: a case study

It is widely accepted that ubiquitous computing (UbiComp) prototyping is one of the methods that can be used to anticipate how future systems are to be designed and what problems can be solved with computational devices. This paper discusses a number of small-scale projects in which researchers attempted to apply some of the UbiComp methodologies to finding solutions to fairly simple problems that surface during everyday campus life. The process aims at finding ways to discover how pervasive technology can affect even the most trivial aspects of human lives as well as trying to make more profound changes. The projects discussed in this paper include a tool for measuring and communicating campus room occupancy, a mobile mode-of-transport detector and a context-aware application for reducing domestic carbon footprint. The applications illustrate the vast possibilities that present mobile platforms offer to the UbiComp researcher and, most importantly, the opportunity to create large numbers of prototypes by numerous users that can be easily evaluated. The authors claim that the software fulfils many UbiComp prototyping requirements and gives great opportunities for field studies. Furthermore, the wide availability of prototyping techniques suggests that computer enthusiasts are now easily immersed in the experience of the UbiComp of the present and the future face of computing can be shaped by many. If, however, one is to verify the applicability of the prototyped systems, even more users must be involved in the UbiComp experience.

Advanced statistical computing for capacitance tomography as a monitoring and control tool

Advanced statistical modelling such as Bayesian framework is a powerful methodology and gives great flexibility in terms of physical phenomena modelling. Unfortunately it is usually associated with very time and resource consuming computing. Therefore it was avoided by engineers in the past. Nowadays, rapid development of computer capabilities enables use of such methods. Algorithms reported here are based on Markov chain Monte Carlo (MCMC) methods applied to Bayesian modelling. The important factor is highly iterative approach enabling direct desired parameters estimation, hence omitting the phase of image reconstruction. This property has an important feature of making feasible implementation of automatic industrial process control systems based on process tomography.

Visualisation of Granular Material Concentration Changes, During Silo Discharging Process, Using ECT Large Scale Sensor

Abstract Measuring changes of bulk materials concentration during gravitational flow, a silo emptying is essential information for the assessment of the behaviour and condition of the material during the emptying of the silo. Parameters obtained during this process are important both in terms of process economics and safety, are the basis for monitoring and diagnostics of the process. Affect the current process, but primarily are the result of their filling the silo, and the process of storing the material. Previous studies, conducted by a team of authors, the laboratory-scale silos and numerical calculations and simulations of its increase, helped build the ECT sensor on a large scale. Results related to the change of scale of the sensor and the actual measurements will be discussed in the article. Proposed by the authors of the paper, the method of visualization, performed in the measuring process, helps to ask about the process and suggests a methodology for dealing with the material stored in the silo.

Gravitational Granular Flow Dynamics Study Based on Tomographic Data Processing

This article presents capabilities of the application of electrical capacitance tomography (ECT) to hopper flow dynamics analysis. The two main goals are to demonstrate a number of tomographic data analysis methods in the application to core flow and to propose some simple parameters depicting this flow via funnel description. Experiments have been conducted for various diameters of hopper orifice using two types of materials with different physicochemical properties, rice and polyamide pellets. ECT allows noninvasive in situ measurement, visualization, and study to be carried out on nonconducting media such as particulate systems or powders. Tomographic images give valuable information about solids concentration distribution inside the measurement space delimited by electrodes. Proper interpretation of concentration changes during the hopper discharging allows the investigation of phenomenon dynamics to be performed. Data analysis consists of raw signal (the measured capacitances) interpretation and tomographic image post-processing manipulation. The present study focuses on the tracking of particulate concentration changes and the hopper discharge rate parameter proposition. Preliminary attempts at funnel propagation velocity measurements are presented here. On the other hand, funnel propagation velocity rate in the initial stage of hopper unloading is based on the calculation of transition time between characteristic points indicated on unloading dynamics diagram. Transition time is calculated using stochastic processes theory-based methods. The novel approach proposed by the authors is based on the estimation of velocity using just one plane of sensing electrodes in contrast to standard applied inter-plane correlation techniques. However, basic parameter estimators such as autocorrelation and variance are used in order to examine the gravitational flow as well.

Bringing the SIGCHI community to Poland: the Łódź Summer School.

the summer school. To our delight, they were happy to listen in during the lectures. We hope we also stirred their interest in HCI. The program had several highlights. On the first lecture day, all participants took a leap of faith and rode a zipline across Manufaktura’s square. This helped lighten the mood in the group. We also hosted a public event where students tested the prototypes they developed during the summer school. They invited local residents to participate and rewarded them with food and drink. Despite a downpour that made the testing extra difficult, many participants enjoyed using the new devices and learning about HCI. It also provided an exercise in popular science for both students and faculty. The school ended with a momentous dinner featuring abundant quantities of local food. P oland’s first major HCI education event took place in July 2017. The SIGCHI-sponsored Łódź Summer School on Methods in HCI invited students from around the globe for an exciting week full of activities. We were lucky to be the organizers of the event. Our plan was simple. We wanted to bring world-class HCI faculty and international HCI students and involve them with local students and communities to foster interest in HCI. The response we got was overwhelming. We were happy to receive support from the Łódź University of Technology (TUL) as well as local businesses. Most important, we got a very high number of applicants. But we were sad to have to turn down more than half. As we wanted the event to be meaningful for our region in particular, we gave priority to students from Central and Eastern Europe. On July 7, the event kicked off with 32 students and 14 lecturers. We began with an opening talk and a dinner to break the ice. The remaining days of the summer school were action-packed! Each morning began with a keynote by an expert on a hot HCI topic. The rest of the days were spent in handson classes focusing on a particular method. On most days we would visit Manufaktura, a former cotton mill turned entertainment center and Łódź’s prime tourist attraction, to engage local users. This “one method a day” program was quite intensive, but it enabled students to get an overview of a variety of methods and pick the ones to study further. We invited local undergraduate students to help with the logistics of We were very glad to see local and international students extend their networks with peers and professors. We have already received reports of research work conducted based on ideas developed during the summer school. Most important, we managed to put HCI on the map in Poland and show its relevance to academics and the public. What’s more, the activities included in the summer school contributed to other initiatives: Shortly after, an HCI student club was established. The school also led to an extended international network, which now supports the process of establishing Poland’s first HCI master’s program. We are grateful to SIGCHI, the organizing universities, our lecturers, and the students for their commitment and support. We believe that the summer school is only the first step toward establishing a strong research and education agenda in Poland and Eastern Europe. The school will have its second edition in the summer of 2019.

Sensing Mobile Device Orientation Through ECT Reconstructed Image Processing

Abstract We present TomoTable—a research prototype of a position sensing device hidden inside an ordinary table. While the Human-Computer Interaction (HCI) field has extensively explored possibilities for spatially-aware multi-device interactions, the sensing methods that would enable such systems are still complex and hard to deploy in the wild. TomoTable presents a possibility of easily deployable invisible positional sensing that uses electrical capacitance tomography (ECT). Electrodes are embedded inside the table structure and provide accurate imaging of what is placed on the table. The entire system is invisible to the user. Objects can be identified based on their electrical properties. Our work creates opportunities for in-the-wild studies using multi-device systems. In this paper, we share the technical concept of TomoTable, preliminary insights on its use and perspectives for future studies.

Diagnostic System of Gravitational Solid Flow Based on Weight and Accelerometer Signal Analysis Using Wireless Data Transmission Technology

Abstract The paper presents results of the scale-up silo flow investigation in based on accelerometer signal analysis and Wi-Fi transmission, performed in distributed laboratory environment. Prepared, by the authors, a set of 8 accelerometers allows to measure a three-dimensional acceleration vector. The accelerometers were located outside silo, on its perimeter. The accelerometers signal changes allowed to analyze dynamic behavior of solid (vibrations/pulsations) at silo wall during discharging process. These dynamic effects are caused by stick-slip friction between the wall and the granular material. Information about the material pulsations and vibrations is crucial for monitoring the interaction between silo construction and particle during flow. Additionally such spatial position of accelerometers sensor allowed to collect information about nonsymmetrical flow inside silo.

Parametric Modelling Algorithms in Electrical Capacitance Tomography for Multiphase Flow Monitoring

Bayesian statistics is a powerful physical phenomena modelling tool. However it usually demands highly iterative algorithms, hence it is was not widely used so far. Recently, rapid development of computing capabilities enables use of such methods. Computing methodology here presented features Markov chain Monte Carlo (MCMC) methods applied to Bayesian modelling. The essential aspect is enabling direct characteristic parameters estimation, hence omitting the phase of image reconstruction widely produced whenever process tomography is applied. This property has an important feature of making feasible implementation of automatic industrial process control systems based on electrical capacitance tomography (ECT)