In the present paper, a procedure is developed for fully automatic recognition of the frontal sinus in cranial radiographs. An X-ray image of a whole skull is required at the input of the procedure, which consists of three subsequent steps: the selection of a rectangular region of interest, containing the sinus; detection of the line of brow ridges; and fronto-nasal suture, detection of the borders of the frontal sinus. The recognition algorithm is based on a method of connectivity-preserving thresholding, introduced in the present study, and on watersheds from markers. Totally, 50 X-ray images have been analyzed. The frontal sinus borders were recognized correctly in 41 cases.
Abstract. The paper presents problems of designing databases for various branches of industry. The development of information technologies and in particular of object-oriented programming has caused a change from data modelling to the modelling of applications. The increase of unstructured Big Data in Industry 4.0 era and requirements of sharing data model between many applications needs a reversion to data analysis and design and it is presented in the article.
Non-metallic inclusions are one of the factors that influence the fatigue strength of steel. Although steel has a relatively small number of non-metallic inclusions, those impurities have a considerable impact on the material's technological and strength parameters, in particular fatigue strength and life. The study was performed on 7 heats produced in an industrial plant. Fourteen heats were produced in 140 ton electric furnaces. The experimental variants were compared in view of the applied melting technology and heat treatment options. The results were presented to account for the correlations between the fatigue strength coefficient during rotary bending, the diameter of and spacing between submicroscopic impurities. Equations for calculating the fatigue strength coefficient at each tempering temperature and a general equation for all tempering temperatures were proposed. Equations for estimating the fatigue strength coefficient based on the relative volume of submicroscopic non-metallic inclusions were also presented. The relationship between the fatigue strength and hardness of high-grade steel vs. the quotient of the diameter of impurities and the spacing between impurities were determined. The analyzed material was one grade of medium-carbon structural steel. The proposed linear regression equations supported the determination of fatigue strength coefficient and bending fatigue strength as a function of hardness taking into account impurities. The proposed equations contributes to the existing knowledge base of practices impact of impurities with various diameters and spacing between non-metalic inclusion on fatigue strength.
The formation of precise products out of difficult to machine materials requires the usage of unconventional techniques and manufacturing technologies; and, above all, it requires adequate knowledge. The worldwide-accepted guidelines in this area are the national and international standards, and corporate experience known as expertise. The aim of this paper is to present the solution to the problem of collecting and sharing data on a variety of materials, within the extended application DBSMP (Database Special Materials Processing). While undertaking the works on the application to support the descriptions of the machining of special materials, it soon became apparent that the fundamental urgency, next to the machining process, is to provide function to the most detailed descriptions of the materials. A draft of the application was prepared with a number of assumptions for the database of standard descriptions and material descriptions, which is presented in this article with an example of high-speed steel.
A lot of elements of agricultural machines are made of Al-Si alloys. Hypoeutectic silumins are among the most popular casting alloys. They are used in a wide range of industrial applications, but their properties are continuously studied to improve the quality of cast products. Attempts are being made to improve the casting technology, refine the microstructure of cast products and enhance their functional properties. Those properties can be altered by cooling, directional solidifications, modification, heat processing and improved production technology. In practice, the properties of alloys are improved mainly through modification. The initial structure of AlSi9Mg alloy is composed of granular and acicular β phase, with α phase as matrix. The hard, irregular, often pointed β phase is responsible for the poor mechanical properties of said alloy. This composition is responsible for the alloy's low strength parameters, and it limits the extent of practical applications. The properties of alloys may not only depend on the chemical composition, modifiers, but may also depend on the conditions of the modification process, which may include the modification time. The analysis of the influence of modifying components in connection with the parameters of the modification process can give wider possibilities of controlling the properties, and thus the use of the alloy. This study presents the results of modification time of an AlSi9Mg alloy with strontium, boron and titanium. The influence of the analyzed modification time on the tensile strength and elongation of silumin modified by Sr, Ti + B was presented in graphs. The used modification treatment time of a hypoeutectic AlSi9Mg alloy improved the alloy's properties. The results of the tests show a change in the mechanical properties of tested alloy.
The article presents the essence and significance of risk management processes in the project, as the key field for successful completion of the project, in the field of project management. Based on literature review, the methods and standards of risk management in the project as well as standards related to process safety were defined. The risk management process according to the PMBoK methodology was discussed as an example of an international project entitled 3DCentral – Catalyzing Smart Engineering and Rapid Prototyping.
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