A significant development of the foundry industry contributes to the creation of high reliability and operational strength castings so that they meet specific standards in accordance with customers’ needs. This technology, however, is inseparably connected with casting defects in finished products. Cast products are subject to various defects which are considered acceptable or not, which is conditioned by the alloy chemical composition and strength characteristics, that is, generally – qualities to be agreed between the foundry and the customer. It is the latter that led the authors to research on designing a tool enabling the most reliable possible assessment of the emerging casting defects, which after proper consultations can be repaired and the casting – sold. The paper presents an original tool named the Open Atlas of Defects (OAD), developed for the last few years to support the evaluation of cast iron defects using Non-Destructive Testing (NDT) casting defects analysis tools (DCC card – Demerit Control Chart, Pareto-Lorenz analysis and ABC analysis). The OAD tool structure was presented as an integral part of the original system module for acquisition and data mining (A&DM) in conjunction with the possibilities of using selected tools for defect analysis support on the example of cast iron casting.
The paper presents an example of Instance-Based Learning using a supervised classification
method of predicting selected ductile cast iron castings defects. The test used the algorithm
of k-nearest neighbours, which was implemented in the authors’ computer application. To
ensure its proper work it is necessary to have historical data of casting parameter values
registered during casting processes in a foundry (mould sand, pouring process, chemical
composition) as well as the percentage share of defective castings (unrepairable casting defects).
The result of an algorithm is a report with five most possible scenarios in terms of
occurrence of a cast iron casting defects and their quantity and occurrence percentage in
the casts series. During the algorithm testing, weights were adjusted for independent variables
involved in the dependent variables learning process. The algorithms used to process
numerous data sets should be characterized by high efficiency, which should be a priority
when designing applications to be implemented in industry. As it turns out in the presented
mathematical instance-based learning, the best quality of fit occurs for specific values of
accepted weights (set #5) for number k = 5 nearest neighbours and taking into account the
search criterion according to “product index”.
The paper contains a short literature review on the subject of special type of thin film structures with resistiveswitching memory effect. In the literature, such structures are commonly labeled as "memristors". The word "memristor" originates from two words: "memory" and "resistor". For the first time, the memristor was theoretically described in 1971 by Leon Chua as the 4th fundamental passive electronics element with a non-linear current-voltage behavior. The reported area of potential usage of memristor is enormous. It is predicted that the memristor could find application, for example in the domain of nonvolatile random access memory, flash memory, neuromorphic systems and so forth. However, in spite of the fact that plenty of papers have been published in the subject literature to date, the memristor still behaves as a "mysterious" electronic element. It seems that, one of the important reasons that such structures are not yet in practical use, is unsufficient knowledge of physical phenomena determining occurrence of the switching effect. The present paper contains a literature review of available descriptions of theoretical basis of the memristor structures, used materials, structure configurations and discussion about future prospects and limitations.
Extensive use of computer networks is associated with the development of various effective methods that are suitable for hiding information in the contents transferred over the network. These methods are described as network steganography. Since web applications use HTTP protocol to transmit the requests to the server and send the answers to the final recipient, specifically HTTP protocol is ideal for hiding information. For example, there are several methods that can be used to transmit the additional content in the HTTP header. In this paper, we present authors’ evaluation method for network steganography using HTTP specific properties and evaluate the effectiveness of some techniques, providing experimental results.
Underwater steel structures require periodic maintenance. In the case of vessels, anti-corrosion works are carried out in the shipyard, where very good conditions for applying organic protective coatings can be provided. Very good surface preparation can be obtained by the use of abrasive blasting. The well-prepared metal surface is free from impurities (particularly inorganic salts). Suitable conditions for the application and renovation of coatings are also ensured (creating appropriate climatic conditions, drying the air, setting the appropriate air temperature). However, there are underwater constructions that cannot be transferred above the water level and, therefore, their conservation against corrosion can take place only under the surface of the water, which significantly hinders the execution of renovation works. In this work, protective coatings for underwater application were tested. The application of coatings on selected steel surfaces over and under the water was carried out. Physico-mechanical and electrochemical tests were carried out in order to assess the quality of the obtained corrosion protection. The possible difficulties faced when applying coatings in marine conditions were discussed.
Titanium dioxide (TiO2) is a popular pigment known as titania white. However, it has many other properties that support various applications.
The article contains a survey of methods of the mobile development with the FMX Application platform, which allows to build multi-platform solutions for the efficient Human-Computer Interaction. The test projects illustrate some important conclusions regarding the design and testing of mobile applications for iOS and Android operating systems. They demonstrate navigation controls designed in the skeumorphic and flat manner with some comparisons based on interviews with users in several age ranges. Test apps provide also touch gestures, sensor integration and connections to remote internet data sources. Some additional considerations about the localization and internationalization of the mobile applications built with the FMX platform were also presented. The proposed implementation of the software engineering methods for the mobile application development provides new insights, valuable for software developers dealing with the new FMX platform on iOS and Android.
In the paper, problem of proper tuning of second-order Reduced Active Disturbance Rejection Controller (RADRC2) is considered in application for industrial processes with significant (but not dominant) delay time. For First-Order plus Delay Time (FOPDT) and Second-Order plus Delay Time (SOPDT) processes, tuning rules are derived to provide minimal Integral Absolute Error (IAE) assuming robustness defined by gain and phase margins. Derivation was made using optimization procedure based on D-partition method. The paper also shows results of comprehensive simulation validation based on examplary benchmark processes of more complex dynamics as well as final practical validation. Comparison with PID controller shows that RADRC2 tuned by the proposed rules can be practical alternative for industrial control applications.
Direct applications in agriculture are among the most prospective development lines of geothermal water and energy. In many countries such uses have already been ongoing. Poland also has suitable natural conditions and geothermal waters’ potential for agricultural development as well as for applications related to agriculture. Moreover, such applications in agriculture – if taking place after earlier use of geothermal waters e.g. for energetic or other purposes – would be the realization of the idea of the closed cycle economy. The first research and development works on geothermal waters and energy applications in agriculture in Poland were carried out in the early 1990s. In recent years this subject has once again sparked a growing interest. The paper presents geothermal water resources potential as well as circumstances, rationale, selected relevant estimations and proposed zones in the country for their uses (as raw material and heat source) in the agricultural sector of the country. The use of geothermal waters in agriculture would be an important element in the chain of agricultural production and agri-food processing, contributing to the increase in the use of locally available natural resources, as well as reducing emissions when using these resources for energetic purposes. The topic is presented against the background of a brief review of the state of geothermal water applications in agriculture in the world and in Europe, which convinces the legitimacy and need for the development of such use of geothermal water as a raw material for agriculture also in Poland.
Choral singers are among intensive voice users whose excessive vocal effort puts them at risk of developing voice disorders. The aim of the work was to assess voice quality for choral singers in the choir at the Polish-Japanese Academy of Information Technology. This evaluation was carried out using the acoustic parameters from the COVAREP (A Collaborative Voice Analysis Repository For Speech Technologies) repository. A prototype of a mobile application was also prepared to allow the calculation of these parameters.
The study group comprised 6 male and 19 female choir singers. The control group consisted of healthy non-singing individuals, 50 men and 39 women. Auditory perceptual assessment (using the RBH scale) as well as acoustic analysis were used to test the voice quality of all the participants. The voice quality of the female choir singers proved to be normal in comparison with the control group.
The male choir singers were found to have tense voice in comparison with the controls. The parameters which proved most effective for voice evaluation were Peak Slope and Normalized Amplitude Quotient.