Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 24
items per page: 25 50 75
Sort by:

Abstract

The results and method of measurements of D, H and T carried out at Hornsund in the summer of 1979 are presented. The relative and absolute values of these elements are given in reduction to the Polish magnetic station at Hornsund. An initial evaluation of changes in the magnetic field from 1957 to 1979 is carried out.
Go to article

Abstract

This paper presents the results of magnetic mapping carried out in the area of the metamorphic series of Ariekammen and Skoddefjellet. On the basis of qualitative interpretation of measurements a number of anomalous zones were distinguished, whose position can be correlated with local changes in mineralitation and polymetallic ore content in the Fuglebergsletta area. The SE-NW orientation, skew to the almost meridional run of the layers of slates and marbles making up the metamorphic complex, dominates in the course of the anomalous zones.
Go to article

Abstract

Investigating human emotions empirically is still considered to be challenging, mostly due to the questionable validity of the results obtained when employing individual types of measures. Among the most frequently used methods to study emotional reactions are self-report, autonomic, neurophysiological, and behavioral measures. Importantly, previous studies on emotional responding have rarely triangulated the aforementioned research methods. In this paper we discuss main methodological considerations related to the use of physiological and self-report measures in emotion studies, based on our previous research on the processing of emotionally-laden narratives in the native and non-native language, where we employed the SUPIN S30 questionnaire as a self-report tool, and galvanic skin response (GSR) as a physiological measure (Jankowiak & Korpal, 2018). The findings revealed a more pronounced reaction to stimuli presented in the native relative to the non-native language, which was however reflected only in GSR patterns. The lack of correlation between GSR and SUPIN scores might have resulted from a number of methodological considerations, such as social desirability bias, sensitive questions, lack of emotional self-awareness, compromised ecological validity, and laboratory anxiety, all of which are thoroughly discussed in the article.
Go to article

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.
Go to article

Abstract

The aim of this paper is to answer the question: Are the Łódź Hills useful for electrical energy production from wind energy or not? Due to access to short-term data related to wind measurements (the period of 2008 and 2009) from a local meteorological station, the measure – correlate – predict approach have been applied. Long-term (1979‒2016) reference data were obtained from ECWMF ERA-40 Reanalysis. Artificial neural networks were used to calculate predicted wind speed. The obtained average wind speed and wind power density was 4.21 ms⁻¹ and 70 Wm⁻¹, respectively, at 10 m above ground level (5.51 ms⁻¹, 170 Wm⁻¹ at 50 m). From the point of view of Polish wind conditions, Łódź Hills may be considered useful for wind power engineering.
Go to article

Abstract

The most popular field methods of measurements of raised marine beach altitudes used by geomorphologists are presented. Compared data from clisimeter routes, altimeter routes and from readings from a photogeological map and directly from air photos compose the profiles. Advantages and disavantages of each method are discussed.
Go to article

Abstract

On the basis of about 12500 depth measurements of which 6700 were taken from r/v Profesor Siedlecki, 1300 from r/v Polarstern and the remainder from British navigation charts, a bathymetric chart of the Bransfield Strait in the scale 1:500 000 has been prepared. Within the assumed boundaries the total area of the Bransfield Strait covers 65308.6 square kilometres, of which the Western Basin covers 23.5%, Central Basin — 47.3%, and Eastern Basin 29.2%. Capacity of the whole Bransfield Strait amounts to 38451 km3 . The average depth of the Bransfield Strait is 592 m.
Go to article

Abstract

The activity of territorial self-government shaped institutionally during the development process is characterized by a significant scope of care for the financial situation, which determines the efficiency of its functioning. The general availability of public services is a condition for the assessment of the activities of municipalities (powiats, voivodeships). Institutional economy as a real one, takes into account an integrated point of view. The aim of the study is to present the territorial differentiation of the eff ectiveness of communes’ activities in the context of institutional economics and to present the possibility of using a synthetic measure in this process. The synthetic measure of development fluctuated within the limits of 0.30 – Wąchock (Starachowice poviat, urban-rural commune) to 0.41 – Ostrowiec Św. (Ostrowiecki poviat, urban commune) in 2009, 0.32 – Łączna (Skarżysko poviat, rural commune) to 0.40 – Starachowice (Starachowice poviat, municipal commune) in 2015. The results of the analysis confirm the existence of small differences in the assessment of development communes of the Kamienna Basin. This approach allows the assessment of municipalities using one size and allows you to organize the analyzed objects in terms of the considered phenomenon.
Go to article

Abstract

A metrological verification of a high precision digital multimeter was made by the laboratory of calibration of programmable electrical multifunction instruments of the National Institute of Metrological Research (INRIM) in order to verify its accuracy and stability. The instrument had been tested for a period of six months for five low-frequency electrical quantities (DC and AC Voltage and Current and DC Resistance). Its stability and precision were compared with the accuracy specifications of the manufacturer. As a new approach, a performance index of the DMM was introduced and evaluated for each examined measurement point. The DMM showed a satisfactory agreement with its specifications to be considered at the level of other top-class DMMs and even better in some measurements points.
Go to article

Abstract

The paper is focused on the main problems of modern metrology in the context of the Fourth Industrial Revolution “Industry 4.0”, particularly in the field of qualimetry. The dominant issues of the methodology of qualimetrical measurement, as the interrelation between metrology and qualimetry, are considered. The following questions are raised and analysed: determination of the measurand in the qualimetrical measurement, creation of the virtual product quality pattern, determination of the product quality level by using the theory of multidimensional scaling, assurance of the metrological traceability of the qualimetrical measurement results. A procedure of performing the qualimetrical measurement is described.
Go to article

Abstract

Four and a half years of African Swine Fever (ASF) in population of free-ranging wild boars and domestic pigs revealed a number of novel insights into the disease epidemiology. Until November 20th, 2018, in total 3048 cases in wild boars and 213 outbreaks in domestic pigs have been confirmed. In spite of low contagiosity as well as low rate of ASF spread in wild boars the disease has an enormous socio-economical impact on the production of pigs in Poland. One of the most important aspects which directly influences the dynamics of ASF spread is the unpredictable hu- man activity. Another important factor responsible for continuous ASF spread is fast recovery of wild boar population in spite of efforts taken by hunters. Assuming our scientific opinion ASF seems to be present in wildlife for the incoming few or several years. Therefore, extraordinary measures should be prepared and undertaken to limit the risk of the occurrence of future out- breaks in domestic pigs. One of the most crucial issues is implementation of strict biosecurity measures in all domestic pigs holdings.
Go to article

Abstract

The efficient protection (support reinforcement) of a wall and heading crossing ensures continuity of the production cycle, and that is a quick moving of the scraper conveyor to the wall. Using low or high bolting as a support reinforcement element in wall and heading crossings allows for the elimination of traditional methods of maintaining longwall-gate crossings, and therefore allows for the efficient use high performance modern wall complexes. The paper presents the long underground experience, of the Knurów–Szczygłowice mine of efficient support wall and heading crossing maintenance, which was bolted to the rock mass with the usage of two pairs of bolts, showing full technical and economical usefulness of this support reinforcement method. The article also highlights work safety and the increasingly common usage of endoscopies when specifying the range of crack areas which directly effects the proper choice in number, load-capacity and length of the used bolts. The underground studies the measurements of the reach of the zones of fracturing and roof stratification (using endoscopes and wire type stratification meters) and the laboratory tests (using the test stand) have allowed to determine the safety factor for maintenance of the longwall gangway crossing, directly resulting in the necessity to install additional reinforcement. The value of the safety factor Sbsc-ch greater than 1 is advantageous and safe, and the value less than or equal to 1 can lead to a significant deterioration of the conditions of maintenance of a wall and heading crossing which was bolted.
Go to article

Abstract

Meteorological conditions at Arctowski Station during 2013–2017 were presented against the background of regional climate changes, especially air temperature decline. Air temperature, relative air humidity, air pressure, solar radiation, wind speed and direction, snow cover and precipitation were collected with an automatic weather station and manual measurements and were further analysed. The obtained results were compared with data from previous years and with data from other stations located on King George Island. Our observations confirm that the vicinity of Arctowski Station experienced a decrease in air temperature during summer, which supports the hypothesis of regional cooling.
Go to article

Abstract

The main purpose of the presented research is to investigate the partial discharge (PD) phenomenon variability under long-term AC voltage with particular consideration of the selected physical quantities changes while measured and registered by the acoustic emission method (AE). During the research a PD model source generating surface discharges is immersed in the brand new insulation mineral oil. Acoustic signals generated by the continuously occurred PDs within 168 hours are registered. Several qualitative and quantitative indicators are assigned to describe the PD variability in time. Furthermore, some longterm characteristics of the applied PD model source in mineral oil, are also presented according to acoustic signals emitted by the PD. Finally, various statistical tools are applied for the results analysis and presentation. Despite there are numerous contemporary research papers dealing with long-term PD analysis, such complementary and multiparametric approach has not been presented so far, regarding the presented research. According to the presented research from among all assigned indicators there are discriminated descriptors that could depend on PD long-term duration. On the grounds of the regression models analysis there are discovered trends that potentially allow to apply the results for modeling of the PD variability in time using the acoustic emission method. Subsequently such an approach may potentially support the development and extend the abilities of the diagnostic tools and maintenance policy in electrical power industry.
Go to article

Abstract

In the paper, the results of investigations on the properties of acoustic emission signals generated in a tested pressure vessel are presented. The investigations were performed by repeating several times the following procedure: an increase in pressure, maintaining a given pressure level, a further increase in pressure, and then maintaining the pressure at new determined level. During the tests the acoustic emission signals were recorded by the measuring system 8AE-PD with piezoelectric sensors D9241A. The used eight-channel measuring system 8AE-PD enables the monitoring, recording and then basic and advanced analysis of signals. The results of basic analysis carried out in domain of time and the results of advanced analysis carried out in the discrimination threshold domain of the recorded acoustic emission signals are presented in the paper. In the framework of the advanced analysis, results are described by the defined by the author descriptors with acronyms ADC, ADP and ADNC. Such description is based on identifying the properties of amplitude distributions of acoustic emission signals by assigning them the level of advancement. It is shown that for signals including continoues AE or single burst AE signals descriptions of such registered signals by means of ADC, ADP and ADNC descriptors and by Upp and Urms descriptors provide identical ordering of registered acoustic emission signals. For complex signals, the description using ADC, ADP and ADNC descriptors based on the analysis of amplitude distributions of recorded signals gives the order of signals with more accurate connection with deformational processes being sources of acoustic emission signals.
Go to article

Abstract

The aim of the paper is to measure and forecast concentration of regional development potential on a regional basis. The study covered 14 GUS features, which measure the development potential. The forecast, nominal values and processes’ dynamics were calculated for data from 2010 to 2020, using author made method. The study reveals that key factors determining the diversification of the distribution of the potential include the relation of large agglomerations to their regional surroundings. Therefore, we are dealing with growth poles with different impact levels. Since 2010, the process of concentrating potential in Poland has taken different directions. In poorly developed regions, we observe constant distribution values. Most regions, especially those with medium and high levels of economic development, are characterized by a dynamic increase in the level of concentration 5% to 6% annually. This means that the growth poles «move away» from their surroundings and strengthen their position. Simultaneously, they slightly reduce the distance to the strongest developed region in Poland (Mazowsze). By 2020, these trends will remain unchanged, however regions with a moderately low level of development will observe the fastest growth.
Go to article

Abstract

There are more and more new development challenges emerging in Polish cities and regions recently. Because of those challenges we can observe an increase of the role of cities and associated environments. The concept of cities’ impact on the environment is a result of many processes, such as: suburbanization, reurbanization, increasing population mobility, development of transport systems, innovation, or entrepreneurship. A city is a complex entity, it is a subject to dynamic changes, to understand which we need interdisciplinary knowledge or the combination of many different approaches along with an attempt to draw many conclusions. We can find numerous theoretical examples describing city-regional environment relations in the literature. In general, these models explain the relationship between economically strong cities (metropolis) and the regions. However, there is not much literature and research explaining the nature and strength of relationships with medium-sized cities. There are also very few ideas for developing the potential of medium-sized cities in polish national policy. The aim of the article is to present disproportions in the development of medium-sized cities in voivodships of Eastern Poland in 2010-2017. The author will also present the possibility of using a synthetic measure to assess and recognize the spatial diversity of medium-sized cities development.
Go to article

Abstract

The methane hazard is one of the most dangerous phenomena in hard coal mining. In a certain range of concentrations, methane is flammable and explosive. Therefore, in order to maintain the continuity of the production process and the safety of work for the crew, various measures are taken to prevent these concentration levels from being exceeded. A significant role in this process is played by the forecasting of methane concentrations in mine headings. This very problem has been the focus of the present article. Based on discrete measurements of methane concentration in mine headings and ventilation parameters, the distribution of methane concentration levels in these headings was forecasted. This process was performed on the basis of model-based tests using the Computational Fluid Dynamics (CFD). The methodology adopted was used to develop a structural model of the region under analysis, for which boundary conditions were adopted on the basis of the measurements results in real-world conditions. The analyses conducted helped to specify the distributions of methane concentrations in the region at hand and determine the anticipated future values of these concentrations. The results obtained from model-based tests were compared with the results of the measurements in realworld conditions. The methodology using the CFD and the results of the tests offer extensive possibilities of their application for effective diagnosis and forecasting of the methane hazard in mine headings.
Go to article

Abstract

This article, as far as possible based on the available literature, empirical measurements, and data from mesoscale models describes and compares expected wind conditions within the Baltic Sea area. This article refers to aspects related to the design and assessment of wind farm wind resources, based on the author’s previous experience related to onshore wind energy. The consecutive chapters of this publication are going to describe the present state and the presumptions relating to the development of wind energy within the Baltic Sea area. Subsequently, the potential of the sea was assessed using mesoscale models and empirical data from the Fino 2 mast that is located approximately 200 kilometers away from the majority of areas indicated in the Polish marine spatial development plan draft of Poland for offshore wind farm development (Maritime Office in Gdynia 2018). In the chapter describing mesoscale models, the author focused his attention on the GEOS5.12.4 model as the source of Modern-Era Retrospective Analysis for Research and Application 2 data, also known as MERRA2 (Administration National Aeronautics and Space Agency, 28), which, starting from February 2016, replaced MERRA data (Thogersen et al. 2016) and have gained a wide scope of applications in the assessment of pre-investment and operational productivity due to a remarkable level of correlation with in-situ data. Model-specific data has been obtained for eight locations, which largely overlap with the locations of the currently existing offshore wind farms within the Baltic Sea area. A significant part of this publication is going to be devoted to the description of the previously mentioned Fino 2 mast and to the analysis of data recorded until the end of 2014 by using the said mast (Federal Maritime and Hydrographic Agency 2018). The analysis has been carried out by means using scripts made in the VBA programming language, making it easier to work with large chunks of data. Measurements from the Fino 2 mast, together with long-term mesoscale model-specific measurements can be used, to some extent, for the preliminary assessment of wind farm energy yield in the areas designated for the development of renewable energy in the Polish exclusive maritime economic zone (Maritime Office in Gdynia 2018). In the final part of this article, pieces of information on the forecasted Baltic Sea wind conditions, especially within the exclusive economic zone of Poland, are going to be summarized. A major focus is going to be put on the differences between offshore and onshore wind energy sources, as well as on further aspects, which should be examined in order to optimize the offshore wind power development.
Go to article

Abstract

Quality evaluation is very important for haptic rendering. In this paper, an objective evaluation method for a haptic rendering system based on haptic perception features is proposed. In the method, the haptic rendering process is compared to the real world perception process in a simple standardized procedure based on feature extraction and data analysis. A complete evaluation process for a simple haptic rendering task of pressing a virtual spring is presented as an example to explain the method in detail. Compared with the traditional objective method based on error statistics, the method is more concerned about the consistency of human subjective feelings rather than physical parameters, which makes the evaluation process more consistent with the haptic perception mechanism. The results of comparative analysis show that the method presented in this paper is simple, gives reliable results reflecting the consistency with subjective feeling and has a better discrimination ability for different kinds of devices and algorithms compared with the traditional evaluation methods.
Go to article

Abstract

In this paper, a modified sound quality evaluation (SQE) model is developed based on combination of an optimized artificial neural network (ANN) and the wavelet packet transform (WPT). The presented SQE model is a signal processing technique, which can be implemented in current microphones for predicting the sound quality. The proposed method extracts objective psychoacoustic metrics including loudness, sharpness, roughness, and tonality from sound samples, by using a special selection of multi-level nodes of the WPT combined with a trained ANN. The model is optimized using the particle swarm optimization (PSO) and the back propagation (BP) algorithms. The obtained results reveal that the proposed model shows the lowest mean square error and the highest correlation with human perception while it has the lowest computational cost compared to those of the other models and software.
Go to article

Abstract

This paper discusses the influence of the direction of applied deformation on the ability to gelation of thermosensitive chitosan hydrogels. The application of the shear rate equal in value to the classically performed oscillatory measurements leads to significantly different shapes of experimental curves. It was found that the type of mechanically applied deformation has a significant impact on the gelation ability of colloidal chitosan solutions and conditions of sol-gel phase transition. Simple shear leads to a phase transition at a lower temperature or in a shorter time compared to oscillatory tests. Moreover, based on the final values of dynamic viscosity in rotational measurements, it was found that stronger crosslinking of the polymer structure was observed.
Go to article

Abstract

Switched reluctance motors (SRMs) are still under development to maximise their already proven usefulness.Amagnetic circuit of theSRMcan be made of soft magnetic composites (SMCs). The SMCs are composed of iron powder with dielectric and have a lot of advantages in comparison to commonly used electrical steel. The paper deals with the modelling and analysis of theSRMproduced by Emerson Electric Co. forwashing machines. Numerical calculations and modelling were done using the FEMM 4.2 program. Magnetic flux densities and magnetic flux lines were calculated, as well as electromagnetic torque and inductance for changing the position of a stator to a rotor. The obtained results were compared with other measurement results and are quite similar. The developed numerical model will be used for the project of a motor with an SMC magnetic circuit.
Go to article

Abstract

The present paper discusses the new Polish law on higher education in the context of the contrasted global and academic paradigms of university funding, governance, and organization. Its point of departure is the advent of international comparative data in higher education, the measurability of individuals, academic units and institutions in terms of research output, and the emergence of a new social contract between the state and universities. The key concepts used to evaluate the new law are competition in science, academic income structure and academic knowledge production structure, internationalists and locals in science, and vertical differentiation in national higher education systems. The new law is assessed in the context of the original reform proposal suggested by the national team of experts led by the present author and its long-term strategic choices are discussed in more detail, including a changing system of institutional evaluation, a revised system of academic degrees, and new excellence-focused national funding schemes.
Go to article

This page uses 'cookies'. Learn more