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Number of results: 20
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Abstract

The paper deals with problem of optimal used automatic workplace for HPDC technology - mainly from aspects of operations sequence, efficiency of work cycle and planning of using and servicing of HPDC casting machine. Presented are possible ways to analyse automatic units for HPDC. The experimental part was focused on the rationalization of the current work cycle time for die casting of aluminium alloy. The working place was described in detail in the project. The measurements were carried out in detail with the help of charts and graphs mapped cycle of casting workplace. Other parameters and settings have been identified. The proposals for improvements were made after the first measurements and these improvements were subsequently verified. The main actions were mainly software modifications of casting center. It is for the reason that today's sophisticated workplaces have the option of a relatively wide range of modifications without any physical harm to machines themselves. It is possible to change settings or unlock some unsatisfactory parameters.

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Authors and Affiliations

A. Herman
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Abstract

Nowadays, there are growing demands on the accuracy of production. Most of this is reflected in precise manufacturing, such as the investment casting process. Foundries are looking for causes of defects in some cases for a very long time, and it may happen that the source of defects is completely different from what was originally assumed. During the casting process there exist potential causes of defects as oxygen inclusions. This paper represents a summary of the beginnings of a wider research that will address the problems of gating systems in investment casting technology. In general, the influence of the melt flow is underestimated and the aim of the whole scientific research is to demonstrate the significant influence of laminar or turbulent flow on the resulting casting quality. Specifically, the paper deals with the analysis of the most frequent types of defects found in castings made of expensive types of materials casted in an open atmosphere and demonstration of connection with the design of gating systems in the future.
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Authors and Affiliations

O. Vrátný
A. Herman
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Abstract

The Author presents in this paper a concept of research on the Jewish ethos internalized in the groups representing main political trends that were popular among the Polish Jewry in the interwar Poland (1918-1939). These trends are: Zionism, Socialism, Folkizm and a policy of Assimilation. Analysis of above group's ethos covers research on the following issues: values and attitudes constituting the ethos of a specific group, sources and function of the ethos and instruments of communication used in transmission of the ethos.
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Authors and Affiliations

Adriana Herman
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Abstract

Head movement is frequently associated with human motion navigation, and an indispensable aspect of how humans interact with the surrounding environment. In spite of that, the incorporation of head motion and navigation is more often used in the VR (Virtual Reality) environment than the physical environment. This study aims to develop a robot car capable of simple teleoperation, incorporated with telepresence and head movement control for an on-robot real-time head motion mimicking mechanism and directional control, in attempt to provide users the experience of an avatar-like third person’s point of view amid the physical environment. The design consists of three processes running in parallel; Motion JPEG (MJPEG) live streaming to html-Site via local server, Bluetooth communication, and the corresponding movements for the head motion mimicking mechanism and motors which acts in accordance to head motion as captured by the Attitude Sensor and apparent command issued by the user. The design serves its purpose of demonstration with the usage of basic components and is not aimed to provide nor research with regards to user experience.
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Bibliography

[1] Janice, “What Is Telepresence Technology?”, 2017. Retrieved from: https://www.eztalks.com/video-conference/what-is-telepresence-technology.html
[2] Malczewski. K.,“The Rise of Telepresence Robots for Business and Beyond”, 2014. Retrieved from: https://www.factor- tech.com/roundup/this-week-facial-recognition-used-to-capture-fugitive-spacex-commits-to-city-to-city-rocket-travel-and-uk-reveals-it-launched-a-cyber-attack-on-islamic-state/
[3] Kerruish, E. “Lessons on telepresence from the Mars explorer Rovers: Merleau-Ponty and the open perceptual circuit. Culture”, Theory and Critique, 1-15, 2019.
[4] Mould, R. F., “Chernobyl record: the definitive history of the Chernobyl catastrophe”, CRC Press, 2000.
[5] Kratz, S., Vaughan, J., Mizutani, R., & Kimber, D. „Evaluating stereoscopic video with head tracking for immersive teleoperation of mobile telepresence robots”. In Proceedings of the Tenth Annual ACM/IEEE International Conference on Human-Robot Interaction Extended Abstracts (pp. 43-44). ACM, 2015.
[6] Wen, M. C., Yang, C. H., Tsai, M. H., & Kang, S. C., “Teleyes: A telepresence system based on stereoscopic vision and head motion tracking”. Automation in Construction, 89, 199-213, 2018.
[7] Pinter, M., Lai, F., Sanchez, D. S., Ballantyne, J., Roe, D. B., Wang, Y., ... & Wong, C. W., U.S. Patent No. 9,776,327. Washington, DC: U.S. Patent and Trademark Office, 2017.
[8] Lester, D. F., Hodges, K. V., & Anderson, R. C., “Exploration telepresence: A strategy for optimizing scientific research at remote space destinations”. Science Robotics, 2(7), Art-No, 2017.
[9] Nakashima, R., & Shioiri, S., “Why do we move our head to look at an object in our peripheral region? Lateral viewing interferes with attentive search”. PloS One, 9(3), e92284, 2014.
[10] Sadik, M. J., & Lam, M. C., „Stereoscopic Vision Mobile Augmented Reality System Architecture in Assembly Tasks”. J Eng Appl Sci, 12, 2098-2105, 2017.
[11] Raja, D. DC Motor Control with Raspberry-Pi, 2016 Retrieved from https://circuitdigest.com/microcontroller-projects/controlling-dc-motor-using-raspberry-pi.

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Authors and Affiliations

Tan Jia Wee
1
Herman Wahid
1

  1. Universiti Teknologi Malaysia, School of Electrical Engineering, UTM Skudai, Malaysia
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Abstract

In earlier works were described trends in the production of tools for die casting (hot work). Almost the entire set of issues dealt with may seem insignificant when incompletely assembled acceptance of the material and the associated risks of processing a material with an inappropriate structure, leading to a very early defect of the die. Therefore, further work will focus particularly on identifying the causes of thermal cracks and preventing a suitable choice of acceptance criteria conditions and heat treatment.

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Authors and Affiliations

A. Herman
P. Zikmund
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Abstract

With increasing technology development, an increasing emphasis is placed on the precision of products, but cannot be guaranteed without a stable production process. To ensure the stability of the production process, it is necessary to monitor it in detail, find its critical locations and eliminate or at least control it. With such a precise manufacturing method as investment casting, such a process is a must. This paper therefore deals with monitoring the production process of wax models of large turbine blades using infrared thermography. The aim was to evaluate the critical locations of this production and to propose recommendations for their elimination or, at the very least, significant mitigation of their impact on the final quality of the large turbine blade casting.

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Authors and Affiliations

A. Herman
O. Vrátný
I. Kubelková
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Abstract

Precision casting is currently motivated by high demand especially for castings for the aerospace, automotive and gas turbine industries. High demands on precision of this parts pressure foundries to search for the new tools which can help them to improve the production. One of these tools is the numerical simulation of injection process, whereas such software especially for investment casting wax injection, process does not exist yet and for this case must be the existing software, for alloys or plastic, modified. This paper focuses on the use of numerical simulations to predict the behavior of injected models of gas turbine blades segments. The properties of wax mixtures, which were imported into the Cadmould simulation software as a material model, were found. The results of the simulations were verified using the results of 3D scanning measurements of wax models. As a supporting technology for verifying the results was used the Infrared Thermography.

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Authors and Affiliations

A. Herman
I. Kubelková
O. Vrátný
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Abstract

The dimensional accuracy of a final casting of Inconel 738 LC alloy is affected by many aspects. One of them is the choice of method and time of cooling the wax model for precision investment casting. The main objective of this work was to study the initial deformation of the complex shape of a rotor blades casting. Various approaches have been tested for cooling a wax pattern. When wax models are air cooled and without clamping in the jig for cooling, deviations from the ideal shape of the casting are very noticeable (up to 8 mm) and most are in extreme positions of the model. When the blade is cooled in the fixing jig in a water environment, the resulting deviations compared to those of air cooling are significantly larger, sometimes up to 10 mm. This itself does not mean that the final shape of the casting is dimensionally more accurate with the usage of wax models, which have smaller deviations from the ideal position. Another deformation occurs when the shell mould is produced around the wax pattern and further deformations emerge while cooling the blade casting. This paper demonstrates the first steps in describing the complex process of deformations occurring in Inconel alloy blades produced with investment casting technology by comparing results of thermal imagery, simulations in foundry simulation software ProCAST 2010, and measurements from a CNC scanning system using a Carl Zeiss MC 850. Conclusions are so far not groundbreaking, but it seems that deformations of the wax pattern and deformations of the castings do in some cases cancel each other by having opposite directions. Describing the whole process of deformations will help increase the precision of blade castings so that the models at the beginning and the blades in the end are the same.

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Authors and Affiliations

A. Herman
M. Česal
P. Mikeš
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Abstract

The paper describes existing requirements for tool materials. In the light of experience with these supplied materials, we have

demonstrated their considerable influence on the life of molds for die casting technology. From this research came the evaluation

methodology of these tool materials which has been used for directing the development of a new material. Based on the new regulation of

the chemical composition a sample was casted and forged after that. Then was determined the process of heat treatment and from a block

of this material a mold insert was produced. This insert is now being tested in production.

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Authors and Affiliations

A. Herman
P. Zikmund
F. Tatíček
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Abstract

Bartlett’s paradox has been taken to imply that using improper priors results in Bayes factors that are not well defined, preventing model comparison in this case. We use well understood principles underlying what is already common practice, to demonstrate that this implication is not true for some improper priors, such as the Shrinkage prior due to Stein (1956). While this result would appear to expand the class of priors that may be used for computing posterior odds, we warn against the straightforward use of these priors. Highlighting the role of the prior measure in the behaviour of Bayes factors, we demonstrate pathologies in the prior measures for these improper priors. Using this discussion, we then propose a method of employing such priors by setting rules on the rate of diffusion of prior certainty.

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Authors and Affiliations

Rodney W. Strachan
Herman K. van Dijk
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Abstract

The work presents the results of experimental study on the possibilities of determining the source of an ultrasonic signal in two-dimensional space (distance, horizontal angle). During the research the team used a self-constructed linear array of MEMS microphones. Knowledge in the field of sonar systems was utilized to analyse and design a location system based on a microphone array. Using the above mentioned transducers and broadband ultrasound sources allows a quantitative comparison of estimation of the location of an ultrasonic wave source with the use of broadband modulated signals (modelled on bats' echolocation signals) to be performed. During the laboratory research the team used various signal processing algorithms, which made it possible to select an optimal processing strategy, where the sending signal is known.

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Authors and Affiliations

Krzysztof Herman
Tadeusz Gudra
Joanna Furmankiewicz
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Abstract

The objective of this research is to determine the impact of waves on the segregation of sediment within the area of its supply in the context of meteorological conditions. The research was conducted on a 4 km section of the shore of Calypsostranda (Bellsund, West Spitsbergen), shaped by waves such as swell, wind waves, and tides. Particular attention was paid to the diversity and variability of the surface texture within the intertidal zone. Meteorological measurements, recording of wave climate, as well as analysis of the grain-size distribution of the beach sediments were performed. Nearshore bathymetry, longshore drifts, episodic sediment delivery from land, as well as resistance of the shore to coastal erosion and direction of transport of sediments in the shore zone are important factors controlling shore development. Data show that wind waves contribute to erosion and discharge of material from the nearshore and intertidal zone. The research also shows that oceanic swell, altered by diffraction, reaching the shore of Calypsostranda contributes to better sorting of sediment deposited on the shore through washing it out from among gravels, and longshore transport of its finest fraction. The grain size distribution of shore sediments is significantly changed already during one tidal cycle. The degree of this modification depends not only on wave height and period but on the direction of wave impact. The shore of Calypsostranda can be regarded as transitional between high and low energy coasts.

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Authors and Affiliations

Piotr Zagórski
Karolina Mędrek
Mateusz Moskalik
Jan Rodzik
Agnieszka Herman
Łukasz Pawłowski
Marek Jaskólski
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Abstract

This paper presents a solution that utilises ultrasonic technology to allow monitoring snow layer thickness or water level based on measurement from air. It describes the principle of operation of a measurement device using three methods of compensating for changing external factors affecting appliance’s precision. Block diagram of the device is also provided. In order to verify the proposed solutions, the research team tested the device in laboratory and operating conditions. The results obtained this way make it possible to select a configuration of device operation depending on the required measurement precision and limitations associated with installing the system for actual operation.
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Authors and Affiliations

Tadeusz Gudra
Dariusz Banasiak
Krzysztof Herman
Krzysztof Opieliński
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Abstract

B a c k g r o u n d: Assessment of the neurocontrol of the external anal sphincter has long been restricted to investigating patients by invasive tools. Less invasive techniques have been regarded less uitable for diagnosis.

O b j e c t iv e: The aim was to develop a surface electromyography-based algorithm to facilitate fecal incontinence diagnosis, and to assess its sensitivity and specificity.

D e s i g n: Data analysis from a single center prospective study.

P a t i e n t s: All patients from colorectal surgery office were considered. They underwent a structured interview, a general physical and proctologic examination. Patients with diagnosed fecal incontinence (Fecal Incontinence Severity Index >10) were included into the study group. The control group consisted of healthy volunteers that scored 5 or less and had negative history and physical exam. Both groups underwent the same tests (rectoscopy, anorectal manometry, transanal ultrasonography, multichannel surface electromyography and assessment of anal reflexes).

M e t h o d s: EMG results were analyzed to find parameters that would facilitate fecal incontinence diagnosis.

O u t c o m e m e a s u r e s: Sensitivity and specificity of surface electromyography, to diagnose fecal incontinence, were assessed.

R e s u l t s: A total of 49 patients were included in the study group (mean age ± SD 58.9 ± 13.8). The control group (n = 49) gender matched the study group (mean age ± SD 45.4 ± 15.1). The constructed classification tree, based on surface electromyography results, correctly classified 97% of cases. The sensitivity and specificity of this classification tree, to diagnose FI, was 96% and 98% respectively.

L i m i t a t i o n s: The age of women in the control group differs significantly from mean age of other groups.

C o n c l u s i o n s: Surface electromyography is an good tool to facilitate diagnosing of fecal incontinence.

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Authors and Affiliations

Michał Nowakowski
Krzysztof A. Tomaszewski
Łukasz Machura
Paulina Trybek
Roman M. Herman
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Abstract

There exists a problem with an in situ diagnostics of contamination of ethyl alcohol in a human being exhaled air. When ethyl alcohol in a mouth blowing (in a gaseous state) exists, the characteristic C–H stretch absorption bands in –CH3 and –CH2 – functional groups in ethanol (CH3–CH2–OH) appear at a wavelength of λ = 3.42 μm. To investigate the presence of ethyl alcohol in exhaled human air, the light beam of λ = 3.42 μm is passing through an air sample. If one alternately measures the intensity of the investigated beam and the reference, a percentage of ethanol in the air sample can be estimated using a sensitive nondispersive infrared (NDIR) system with a stable operating flow mass detector. To eliminate a mechanical chopper and noise generating stepper motors, a photonic chopper as a liquid crystal shutter for λ = 3.42 μm has been designed. For this purpose, an innovative infrared nematic liquid crystal mixture was intentionally prepared. The working mixture was obtained by a selective removal of CH bonds and its exchange by heavier polar substituents, what ensures a lack of absorption band of C–H bonds. The paper presents theory, concept and final experimental results of the infrared nematic liquid crystals mixture and the liquid crystal shutter for breathalyzer applications.

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Authors and Affiliations

W. Piecek
L. Jaroszewicz
E. Miszczyk
Z. Raszewski
M. Mrukiewicz
P. Kula
K. Jasek
P. Perkowski
E. Nowinowski-Kruszelnicki
J. Zieliński
J. Kędzierski
M. Olifierczuk
U. Chodorow
P. Morawiak
R. Mazur
K. Kowiorski
P. Harmata
J. Herman

Authors and Affiliations

Krzysztof Klimaszewski
Sebastian Borucki
Jacek Łuczak
Dariusz Zmarzły
Michał Kunicki
Andrzej Cichoń
Franciszek Witos
Czesław Leśnik
Dariusz Pleban
Milan Timko
Tomasz Rogala
Piotr Serafin
Tadeusz Gudra
Jerzy Filipiak
Dariusz Banasiak
Krzysztof Herman
Krzysztof Opieliński
Tomasz Hejczyk
Krzysztof Jasek
Mateusz Pasternak
Michał Grabka
Witold Kardyś
Andrzej Milewski
Adam Kawalec
Marta Okoń-Fąfara
Bartłomiej Fąfara
Aneta Olszewska
Piotr Pruchnicki
Marcin Wrzosek
Józef Nicpoń
Przemysław Podgórski
Tadeusz Pustelny
Marcin Szugajew
Olga Stec
Grzegorz Szerszeń
Daria Wotzka
Agnieszka Boruń
Adam Bald
Marzena Dzida
Sylwia Jężak
Monika Geppert-Rybczyńska
Katarzyna Kaczmarek
Tomasz Hornowski
Arkadiusz Józefczak
M. Kubovčíková
A. Skumiel
Z. Rozynek
M. Timko
Peter Kopcansky
Bogumił Linde
Vyacheslav N. Verveyko
Marina V. Verveyko
Darya V. Verveyko
Andrey Yu. Verisokin
Nikita S. Chebrov
Witold Mikulski
Danuta Augustyńska
Bożena Smagowska

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