scholarly journals STRUCTURAL-PARAMETRIC MODEL OF SECOND-ORDER SURFACES

Author(s):  
Gennadii Virchenko ◽  
Olga Golova ◽  
Oleksii Vorobyov ◽  
Tetjana Nadkernichna ◽  
Julia Lazarchuk-Vorobyova

One of the modern directions for the further development of the applied geometry scientific school of the Igor Sikorsky Kyiv Polytechnic Institute is the structural-parametric shaping of various technical objects. Currently, the general theoretical foundations of this methodology and specialized means of its practical implementation are being developed. The results obtained in the design, manufacture and operation of specific industrial products largely depend on their efficiency. The created mathematical models serve as the basis for software modules, which become components of the applied computer information systems. In these conditions, the issues of developing the necessary methodological support are also important. From the side of the theory of structural-parametric shaping, requirements are imposed on new geometric means in accordance with the principles of universality and unification, variability, openness and development, a system approach, etc. As can be seen from the title of the publication, in our case we are talking about second-order surfaces, which, due to their useful properties, are quite common in many technical objects. Note that the plane is considered a simplified version of these figures. The indicated universality and unification consist in solving a wide range of problems using the same type of methods, techniques, algorithms, etc. Variability is the need to implement for the geometric model of its flexible and productive use, the openness and the development – of easy updating, expansion and improvement its components. The systems approach requires considering the created mean not only as interconnected elements, but also as a part of systems of a higher hierarchical level. The submitted second-order surface model satisfies the rules described above. Its main peculiarity lies in the combination of the vector definition of these items with the structural-parametric methodology. The developed techniques of shaping are suitable for wide practical use during the automated design of various technical objects, the processes of their production and operation.

2019 ◽  
pp. 40-46 ◽  
Author(s):  
V.V. Savchenko ◽  
A.V. Savchenko

We consider the task of automated quality control of sound recordings containing voice samples of individuals. It is shown that in this task the most acute is the small sample size. In order to overcome this problem, we propose the novel method of acoustic measurements based on relative stability of the pitch frequency within a voice sample of short duration. An example of its practical implementation using aninter-periodic accumulation of a speech signal is considered. An experimental study with specially developed software provides statistical estimates of the effectiveness of the proposed method in noisy environments. It is shown that this method rejects the audio recording as unsuitable for a voice biometric identification with a probability of 0,95 or more for a signal to noise ratio below 15 dB. The obtained results are intended for use in the development of new and modifying existing systems of collecting and automated quality control of biometric personal data. The article is intended for a wide range of specialists in the field of acoustic measurements and digital processing of speech signals, as well as for practitioners who organize the work of authorized organizations in preparing for registration samples of biometric personal data.


2020 ◽  
Vol 26 (1) ◽  
pp. 86-93
Author(s):  
D. V. Slivinsky ◽  
I. A. Fomina ◽  
D. G. Menshikh

The presented study determines the role of business aviation in the modern economy and examines the specific features of its development in Russia.Aim. The study aims to analyze the development of business aviation in Russia and its correlation with economic development in general.Tasks. The authors determine the benefits of business aviation as a business tool, examine the specific features of the Russian business aviation market and problems of its development, and identify factors that affect the development of business aviation in Russia.Methods. This study uses the methods of comparative and retrospective analysis, cross-country comparison, systems approach, and expert analytics.Results. Business aviation is a new segment of civil aviation for Russia. Therefore, it is advisable to rely on foreign practices in the management of its development. In many countries, business aviation is a separate industry that specializes in providing transport services to a wide range of corporate clients and/or individuals. The development of this industry is associated with the economic growth rate and the development level of the national economy, and also depends on the national institutional specifics. This study describes the specific features of development of business aviation in Russia and problems arising in the organization and management of this type of business.Conclusions. The authors develop a system of factors affecting the development of business aviation in Russia, describe the major problems of this industry, and propose solutions. The results of this study can be used in the development (adjustment) of business aviation development strategies in Russia both at the industrial and corporate level, and in the implementation of the national policy in this field.


2013 ◽  
Vol 6 (1) ◽  
pp. 453-494 ◽  
Author(s):  
D. S. Moreira ◽  
S. R. Freitas ◽  
J. P. Bonatti ◽  
L. M. Mercado ◽  
N. M. É. Rosário ◽  
...  

Abstract. This article presents the development of a new numerical system denominated JULES-CCATT-BRAMS, which resulted from the coupling of the JULES surface model to the CCATT-BRAMS atmospheric chemistry model. The performance of this system in relation to several meteorological variables (wind speed at 10 m, air temperature at 2 m, dew point temperature at 2 m, pressure reduced to mean sea level and 6 h accumulated precipitation) and the CO2 concentration above an extensive area of South America is also presented, focusing on the Amazon basin. The evaluations were conducted for two periods, the wet (March) and dry (September) seasons of 2010. The statistics used to perform the evaluation included bias (BIAS) and root mean squared error (RMSE). The errors were calculated in relation to observations at conventional stations in airports and automatic stations. In addition, CO2 concentrations in the first model level were compared with meteorological tower measurements and vertical CO2 profiles were compared with aircraft data. The results of this study show that the JULES model coupled to CCATT-BRAMS provided a significant gain in performance in the evaluated atmospheric fields relative to those simulated by the LEAF (version 3) surface model originally utilized by CCATT-BRAMS. Simulations of CO2 concentrations in Amazonia and a comparison with observations are also discussed and show that the system presents a gain in performance relative to previous studies. Finally, we discuss a wide range of numerical studies integrating coupled atmospheric, land surface and chemistry processes that could be produced with the system described here. Therefore, this work presents to the scientific community a free tool, with good performance in relation to the observed data and re-analyses, able to produce atmospheric simulations/forecasts at different resolutions, for any period of time and in any region of the globe.


2021 ◽  
Vol 11 (15) ◽  
pp. 7122
Author(s):  
Simona Mosca ◽  
Tobias Hansson ◽  
Maria Parisi

Optical frequency comb synthesizers with a wide spectral range are an essential tool for many research areas such as spectroscopy, precision metrology, optical communication, and sensing. Recent studies have demonstrated the direct generation of frequency combs, via second-order processes, that are centered on two different spectral regions separated by an octave. Here, we present the capability of optical quadratic frequency combs for broad-bandwidth spectral emission in unexplored regimes. We consider comb formation under phase-matched conditions in a continuous-wave pumped singly resonant second-harmonic cavity, with large intracavity power and control of the detuning over several cavity line widths. The spectral analysis reveals quite distinctive sidebands that arise far away from the pump, singularly or in a mixed regime together with narrowband frequency combs. Notably, by increasing the input power, the optical frequency lines evolve into widely spaced frequency clusters, and at maximum power, they appear in a wavelength range spanning up to 100 nm. The obtained results demonstrate the power of second-order nonlinearities for direct comb production within a wide range of pump wavelengths.


1983 ◽  
Vol 27 (1) ◽  
pp. 70-74
Author(s):  
Klaus M. Blache

A workable “systems approach” ergonomics program must be comprehensive, yet practicable in application. In order of the evolutionary development of Fisher Body's Manufacturing Ergonomic Program, data analysis, workplace analysis, recommended changes, training, reporting and evaluating progress and future planning are discussed. Emphasis throughout is put on practical implementation.


Author(s):  
J. Rosen ◽  
D. Johnstone ◽  
P. Sincock ◽  
A. E. Potts ◽  
D. Hourigan

Life extension and asset integrity of Floating Production Unit (FPU) moorings are issues of increasing importance for operators due to changing production requirements, the requirement to extend service life, and circumstances where the met-ocean Basis of Design (BOD) has increased significantly over the life of the field. Reliability methods are gaining increasing acceptance as increased computing power allows large numbers of simulations to be undertaken using realistic fully coupled models that are validated against prior experiments. When applied to the re-qualification and life extension of FPU moorings, particularly with regard to re-qualification and life extension of in-place moorings, reliability analysis offers considerable advantages over conventional deterministic return period design. This paper details the application of a reliability approach to re-qualification and life extension of a turret-moored FPU that had design met-ocean conditions increased significantly over the life of the field. It explores key elements of reliability analysis including the probabilistic characterisation of met-ocean conditions, adequate representation of vessel dynamics and mooring loads in a Response Surface Model, and a selection of algorithms to solve for the system probability of failure. Discussion points include the advantages of the explicit identification of the most likely failure scenario versus uncertainty as to whether the worst design case has been identified, and the potential for rapid reassessment of reliability for specific design conditions (such as a degraded mooring system or a system for which degradation is ongoing). The results of this study demonstrate the significant advantages to the industry conferred by adopting reliability methods in the re-certification and life extension of existing FPU moorings. In particular, the study highlights that conventional mooring code deterministic design methods, whilst adequate for original design purposes, lack sufficient fidelity to address the multi-faceted issue of re-assessment of notionally marginal legacy systems. For a degraded existing mooring, an application of these methods can demonstrate that the level of reliability of the system is still acceptable, whereas a conventional approach may produce an over-conservative indication that the mooring is non-compliant. Applicable to a wide range of FPUs requiring re-qualification or life extension, the techniques discussed also provide pointers to more efficient and reliable mooring design for not just existing, but also for new FPUs.


Author(s):  
Evan Barba

Second-order effects refer to changes within a system that are the result of changes made somewhere else in the system (the first-order effects). Second-order effects can occur at different spatial, temporal, or organizational scales from the original interventions, and are difficult to control. Some organizational theorists suggest that careful management of feedback processes can facilitate controlled change from one organizational configuration to another. Recognizing that skill in managing feedback processes is a core competency of design suggests that design skills are potentially useful tools in achieving organizational change. This paper describes a case study in which a co-design methodology was used to control the second-order effects resulting from a classroom intervention to create organizational change. This approach is then theorized as the Instigator Systems approach.


Vestnik IGEU ◽  
2019 ◽  
pp. 58-66
Author(s):  
I.Yu. Dolgikh ◽  
M.G. Markov

A wide range of technological advantages of induction crucible melting furnaces makes their use in various sectors of metallurgical production relevant. However, hard operation conditions of the refractory lining of such furnaces makes it necessary to constantly monitor its condition, with the aim to extend the crucible life and prevent emergencies. Moreover, traditional methods based on the use of a bottom electrode and indication of current leakage to earth do not provide a continuous display of the lining destruction degree and make it possible to register only a critical level that requires an emergency shutdown and emptying of the furnace. This circumstance makes it necessary to develop and implement specialized electrical systems with a monitoring and control system that ensures the determination and visualization of the lining wear level and, if necessary, makes an emergency shutdown of the equipment from the power source. The developed complex is based on a microprocessor system that continuously measures the temperature at the control points at the boundary between the bottom and crucible base layers and compares the obtained values with the settings, which are determined previously on a two-dimensional axisymmetric model of the designed furnace by solving the stationary heat conduction equation at various levels of lining failure. We have developed the structure, scheme, and program for a microprocessor-based monitoring and emergency shutdown system of an induction furnace, as well as a mathematical model of the control object, which allows determining the temperature settings. The reliability of the results is confirmed by the applicability of the models to real objects, and is verified by debugging the microprocessor part in the MPLab-Sim and Proteus programs. The obtained results can be used in the practical implementation of the monitoring system and emergency shutdown of induction melting furnaces, which allows increasing the safety of their operation and extending the lining life due to timely repair.


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