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Applied Computer Science Volume 12, Number 3, 2016

NUMERICAL ANALYSIS AND EXPERIMENTAL INVESTIGATION OF DISK SPRING CONFIGURATIONS WITH REGARD TO LOAD CAPACITY OF SAFETY PROGRESSIVE GEARS

 

The paper investigates the effect of various disk spring package configurations on brake load of safety progressive gears. The numerical analysis is performed using the Abaqus/CAE software and the designed 3D models. The numerical results are then verified in experimental tests. The tests also examine the effect of lubrication on brake load of spring packages. In addition, the paper investigates the work conditions of safety progressive gears at emergency braking. The experimental results show agreement with the numerical results.

PRIOR IMAGE JPEG-COMPRESSION DETECTION

 

The paper presents two methods of prior JPEG-compression detection.In the first method the histogram of chrominance is analysed. In JPEG-compressed images the  histogram contains significantly more local maxima than in uncompressed files. The second method is based on neighbouring pixel O value difference. In JPEG-compressed image the distribution of these values is different than the distribution counted on the edges of compression 8x8 blocks. These differences are summed up to create a classifier that allows to assess if the image was compressed.

CHARACTERISTICS OF PRODUCTS MADE OF 17-4PH STEEL BY MEANS OF 3D PRINTING METHOD

The article presents the results of tests of 17-4PH steel fabricated by means of the method consisting in laser additive manufacturing (LAM) – direct metal laser sintering (DMLS). This grade of steel is characterized by excellent stress corrosion resistance in the first place and is applied as construction material in chemical, aircraft, medical or mould making industry. 3D metal printing is a relatively new method enabling significant change of structural properties of these materials at printing parameters predetermined by printers manufacturer for ”offline” printing mode.In order to achieve this goal, the authors have carried out the analysis of chemical composition, SEM tests and the tests of products surface roughness. Furthermore the products have been subjected to X-ray analysis by means of computed tomography (X-ray CT). Structural discontinuities have been found in upper layer and inside printouts subjected to tests.

PERSPECTIVES FOR FOG COMPUTING IN MANUFACTURING

This article discusses ongoing efforts to enable the fog computing vision in manufacturing. As a new paradigm of computing implementation of fog computing faces many challenges that open perspective of new applications within a field of manufacturing. It is expected that fog computing will be one of factors that will accelerate development of in forth industrial revolution. In this article we discuss the perspectives of manufacturing companies surrounded by new solutions of CPS, CPPS and CM in relation to fog computing.

COMPUTER MODELLING OF ENERGY SAVING EFFECTS

The paper presents the analysis of the dynamics of the heat transfer through the outer wall of the thermal technical spaces, taking into account the impact of the sinusoidal nature of the changes in atmospheric temperature. These temporal variations of the input on the outer surface of the chamber divider result at the output of the sinusoidal change on the inner wall of the room, but suitably suppressed and shifted in phase. Properly selected phase shift is clearly important for saving energy used for the operation associated with the maintenance of a specific regime of heat inside the thermal technical chamber support. Laboratory tests of the model and the actual object allowed for optimal design of the chamber due to the structure of the partition as well as due to the orientation of the geographical location of the chamber.

MODELLING OF CHARACTERISTICS OF TURNING OF SHAFTS WITH LOW RIGIDITY

Numerical studies were conducted with the use of a computer program permitting the determination of the basic dynamic characteristics of the process of machining and the presentation of graphic characteristics of the numerical simulations performed. Analysis was performed of the relation of the output parameters of the dynamic system to the input parameters, relative stiffness coefficient B to feed rate and depth of machining, change of retardation and time constants to rotary speed and depth of machining, and of the frequency and time characteristics of models of the dynamic system of machining of shafts with low rigidity.

CALCULATION METOD FOR THE EVALUATION OF INFLUENCE OF TOOTH ENGAGAMENT PARITY IN CONICAL SPUR GEAR ON CONTACT PRESSURES, WEAR AND DURABILITY

The paper presents the results of research undertaken to determine maximum contact pressures, wear and life of conical gears, taking account gear technological correction, tooth engagement and wear-generated changes in curvature of their involute profile. The calculations were made for a reduced cylindrical gear using a method developed by authors. The effect of applied conditions of tooth engagement in the frontal and internal sections of cylindrical gear ring is shown graphically. The initial maximum contact pressures will be higher in the internal section and the highest at the entry of single tooth engagement; the increasing of correcting coefficients will cause the fall of contact and tribocontact pressures; the optimum values of correction coefficients, at which the durability of the gear will be the highest were obtained.

COMPUTER APPLICATION SYSTEM FOR OPERATIONAL EFFICIENCY OF DIESEL RAILBUSES

The article presents a computer algorithm to calculate the estimated operating cost analysis rail bus. This computer application system compares the cost of employment locomotive and wagon, the cost of using locomotives and cost of using rail bus. An intensive growth of passenger railway traffic increased a demand for modern computer systems to management means of transportation. Described computer application operates on the basis of selected operating parameters of rail buses.