63 results
Search Results
2. EVOLUTIONARY PLANNER OF 3D TRAJECTORIES.
- Author
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Ćurković, Petar and Čehulić, Lovro
- Subjects
- *
EVOLUTIONARY algorithms , *TRAJECTORIES (Mechanics) , *STOCHASTIC convergence , *MATHEMATICAL optimization , *MATHEMATICAL analysis - Abstract
This paper presents a method based on evolutionary algorithms for the planning of robotic trajectories both in 2D and 3D space. Space can be arbitrary shaped containing randomly sized and distributed obstacles. Different methods were implemented and evaluated for improving the speed and the level of the convergence of the algorithm. It is shown that evolutionary algorithm in its simplest form cannot effectively solve this problem in 3D. A thorough statistical analysis is performed for various instances of the algorithm, and the best algorithmic procedures are identified, documented, and explained in the paper. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
3. MODELLING AND SIMULATING A CONTROLLED PRESS-BRAKE SUPPLY SYSTEM.
- Author
-
Lovrec, D. and Kastrevc, M.
- Subjects
MACHINERY ,SIMULATION methods & models ,ELECTROHYDRAULIC effect ,MATHEMATICAL models ,MECHATRONICS ,AUTOMOBILE industry ,MATHEMATICAL analysis ,DECISION making - Abstract
Modern machinery and equipment manufacturers incorporate advanced technology into their products. This is especially true for those applications where an electro-hydraulic supply system is used, e.g. on tool and metal shaping/forming machines. Such machines represent a complex and multitechnological mechatronic system, and should be first modelled and simulated, especially in respect of dynamic behaviour. This paper presents a theoretical analysis of an energy-saving and cost-effective electro-hydraulic supply system on a hydraulic press-brake, used within the automotive industry. It emphasises the designing an adequate mathematical-simulation model, to serve as the basis for decisions concerning the used supply system's dynamic. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
4. SIMULATING THE MAGNETRON SPUTTERING PROCESS FOR INDUSTRIAL APPLICATIONS.
- Author
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Spataru, Ionuţ, Nicolescu, Adrian, Coman, Cezara, Cristoiu, Cozmin, and Ivan, Andrei
- Subjects
- *
MAGNETRON sputtering , *INDUSTRIAL applications , *PHYSICAL vapor deposition , *SURFACE coatings , *MATHEMATICAL analysis , *SIMULATION methods & models - Abstract
This paper presents a new method of simulating the process of thin layer glass coating by magnetron sputtering on real industrial scale equipment and in real industrial application as well as necessary experimental results for the validation of the new developed mathematical formulation and software algorithm. Based on major differences between applications realized with laboratory equipment studied until now by other authors and the real scale industrial installations analyzed in present paper, development of a new mathematical model, simulation method and process control of magnetron sputtering systems by ionized physical vapor deposition (IPVD) was needed. Improvement of the deposition process by applying this new concept on industrial scale is discussed for different material types, specific deposition energy levels and the uniformity of the deposed layers based on simulation and experimental results analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
5. Some Mathematical Considerations on the Natural Protection of the Danube Delta Coastal Zone in Romania.
- Author
-
Petrescu, Nicolae, Mircea, Sevastel, Tronac, Augustina, and Manole, Emilia
- Subjects
- *
MATHEMATICAL analysis , *FRESHWATER ecology , *CLIMATE change , *LITTORAL zone , *WIND waves , *COASTAL engineering - Abstract
Today, more and more scientists agree with the hypothesis concerning the raising of the planetary ocean level due to global climate warming and consequently due to glaciers melting. Therefore, as a consequence of climate change phenomenon, the Black Sea level is raising as well, which led to the loss of significant areas of land due to marine erosion, but also the production of some cracks and penetration of salt water into the Razelm - Sinoe freshwater ecosystem in Romania. This paper uses a mathematical tool, which addresses the maintenance of the ecological balance of freshwater ecosystem, the transit of freshwater through the Razelm - Sinoe hydrotechnical complex, and from here into the Black Sea, required to ensure the hydraulic gradient from freshwater to saltwater. This would help maintaining vegetation as natural means for protection against the sea erosion, as well as to attenuate the coastal energy of waves, so as to ensure the shielding role together with the other coastal engineering construction. Besides, the strong reed vegetation represents a natural element of protection of levees already made or those in process of development, and also a retention element of fine particles brought by waves at times when sea level is high. The mathematical algorithm used in this paper take into account the principle of fluid flows in porous media. The vegetation of littoral from Razelm - Sinoe ecosystem was considered a porous media. The research results show the capacity of the vegetation to attenuate the waves' energy in the study area. The mathematical model was especially conceived for a unique littoral area, which separates the Black Sea from Razelm - Sinoe ecosystem. The solution of protection exploits the natural environment; it is not expensive and falls into the natural-ecological aspect of the coastal zone. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
6. ANALYSIS OF SOLAR ENERGY POTENTIAL AND OPTIMAL PANEL TILT ANGLE IN THE AREA OF THE CITY OF SARAJEVO.
- Author
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Djikic, Berin, Hadziahmetovic, Halima, Cerimovic, Hamza, Ahmovic, Ismira, and Blazevic, Rejhana
- Subjects
- *
POTENTIAL energy , *SOLAR energy , *FOSSIL fuels , *METROPOLIS , *MATHEMATICAL analysis - Abstract
One of the major problems the city of Sarajevo is currently facing is the fact that in winter months the atmosphere is very polluted, mainly because of enormous usage of fossil fuels, primarily for heating. The other issue is the fact that it is extremely energy dependent, only a small portion of it’s energy needs is currently produced within the area of the city. These are the two main reasons for the analysis of the solar energy potential in Sarajevo. This paper focuses on analysing the available solar irradiance data obtained from several sources and on providing the exact mathematical method of the analysis, as well as on the results themselves. Furthermore, it also focuses on the effect of the surface tilt angle on the overall amount of the solar irradiance received by the tilted surface. After analysing and processing al the data, a more precise assessment of solar energy potential and the effect of the tilt angle on the overall irradiance received by the tilted surface in Sarajevo is given, as well as the guidelines for further research. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
7. CONSISTENCY CHECK OF FUZZY PAIRWISE COMPARISON MATRICES OF DIMENSIONS LARGER THAN 3X3.
- Author
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Lavic, Zedina, Vucijak, Branko, Pasic, Mugdim, and Dukic, Nedzad
- Subjects
- *
FUZZY sets , *MATRICES (Mathematics) , *MATHEMATICAL models , *NUMERICAL analysis , *MATHEMATICAL analysis - Abstract
In decision-making models based on the Fuzzy Analytic Hierarchy Process, it is necessary to check the consistency of the fuzzy pairwise comparisons matrices. The consistency of the fuzzy matrix 3x3 can be checked on the basis of the similarity of the fuzzy numbers. In this paper, it is shown how to check the consistency of matrices of larger dimensions by decomposing these matrices to the 3x3 matrices. The consistency check of fuzzy matrices by decomposition is shown for pairwise comparisons matrices obtained by using fuzzified Saaty's scale. The direction for future research is proposed. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
8. DETERMINING THE STRENGTH OF COMPOSITE CYLINDRICAL BONDED JOINTS USING NUMERICAL SIMULATION WITH COHESIVE ELEMENTS.
- Author
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Sedlacek, Frantisek, Kalina, Tomas, and Raab, Zdenek
- Subjects
- *
JOINTS (Engineering) , *COHESIVE strength (Mechanics) , *ADHESIVES , *NUMERICAL analysis , *MATHEMATICAL analysis - Abstract
The adhesive joints belongs into most used connection in area of the composite components. The prediction of the strength of the bonded joints is still very problematic and many approaches can be used to dimension them. The paper deals with determining the strength of cylindrical composite adhesive joint using numerical simulation. In this case is used numerical simulation based on the finite element approach and cohesive elements were used as substitution of the adhesive. The experimental measurements were done for determination of necessary parameters of behaviour of gluing for cohesive zone model according ASTM standards. The parameters for mode I was determined by double cantilever beam test and the end notched three point bending test was carried out fo r finding parameters of mode II. Based on the obtained parameters, verification was performed on cylindrical s amples with the accuracy up to 6%. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
9. STRUCTURES OF AUTOMATIC SYSTEMS WITH UNSTABLE PARAMETERS (PART II).
- Author
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Potapov, A., Stazhkov, S., Dalyaev, J., and Ohochinsky, M.
- Subjects
- *
AUTOMATION , *PARAMETERS (Statistics) , *MATHEMATICAL models , *NUMERICAL analysis , *MATHEMATICAL analysis - Abstract
In the first part of the research work it was offered to apply the desirable structures of system with the maximum degree of stability for automatic systems with unstable parameters. An example was given to show the effectiveness of the approach. Recommendations on the synthesis of the 4th order structures were given. In this paper the structures of 5 ÷ 8 orders are presented and a general method for the synthesis of the arbitrary order structures are given. It is shown that to build the desirable structure with real roots a non-stiff system of equations can be obtained and solved. Also, a method for selecting a structure based on the required parameters is proposed. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
10. SCREEN ELEMENT SHAPE "R73" MUTATION.
- Author
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Pap, K., Ziljak, J. Vujic, Ziljak, I., and Agic, D.
- Subjects
STOCHASTIC analysis ,MUTATION testing of computer software ,MATHEMATICAL analysis ,STOCHASTIC processes ,MATHEMATICAL models ,THREE-dimensional imaging ,BOUNDARY value problems ,DIFFERENTIAL equations ,COMPLEX variables - Abstract
The paper describes research on creating a new shape of screening cell definition that has not even existed to date. Therefore it has not been researched nor applied yet. A novelty of this paper is that unlike former research where one screening shape was treated in the overall reproduction, this paper presents screening that applies an indefinite number of screening models and screening shapes in the same page. The "R73" mutating screen element shape is shown with a newly developed method of screen element shape growth function parameterization and stochastic functionality implementation. The research methods for testing growth function boundary conditions are 2D and 3D mathematical modelling. The mutation parameter has been designed in such a way that its application alters the screen element shape from a symmetric shape to an asymmetric one. Due to this transformation of shape the authors have named them mutants. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
11. A MATHEMATICAL MODEL OF AN ARTIFICIAL COCHLEA BASED ON AN ARRAY OF RESONATORS.
- Author
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Dusek, D.
- Subjects
RESONATORS ,COCHLEA ,SPECTROGRAMS ,SOUND spectrography ,SOUND ,HEARING ,SIGNAL processing ,MATHEMATICAL models ,MATHEMATICAL analysis - Abstract
This work considers using of an array of resonators for non-stationary signal decomposition. A simple mathematical model of the array of resonators which is compound from masses with springs is presented and described in this paper first. Subsequently spectrograms of known test function for different values of viscous damping and for different values of connection spring stiffness calculated by the mathematical model of the array of resonators are presented. After the verification of the mathematical model by the known test signal also spectrograms of random non-stationary signal were calculated and they are also presented in this paper. The results showed that the array of resonators is able to decompose whatever non-stationary signals in very good quality if suitable damping of resonators and interaction between resonators is used. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
12. A NEW APPROACH IN WORKSPACES ANALYSIS FOR ROTARY ENGINES CASE.
- Author
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Chioreanu, N. and Catas, A.
- Subjects
ROTARY combustion engines ,WANKEL engine ,INTERNAL combustion engines ,DIESEL motor pistons ,COMBUSTION chambers ,PATENTS ,ENGINES ,MATHEMATICAL optimization ,MATHEMATICAL analysis - Abstract
Within this paper the authors provide new aspects concerning operating principles of a certain rotary piston heat engines, namely Wankel engine and Panu-Stanescu engine, the last one is a Romanian letters-patent of engineers Mihai Panu and Gheorghe Stanescu. Taking in consideration the work spaces with variable volume which are created during the engine running, the authors develop a theoretical approach of the determination of the volume function variation in the Wankel rotary engine case. The paper presents the parameter equations of the inner surface sections of the carcasses of the piston section and the determination of the volume function variation of one chamber, in each case. Due to this fact one can obtains an optimization of the operational factors in the case of the above mentioned rotary piston heat engines. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
13. AN APPLIED ELASTICITY COMMON SENSE PERSPECTIVE AND THE OPTIMAL DESIGN.
- Author
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Oanta, E.
- Subjects
STRENGTH of materials ,ELASTICITY ,PROPERTIES of matter ,OPTIMAL designs (Statistics) ,EXPERIMENTAL design ,MATHEMATICAL optimization ,COMPUTER algorithms ,MATHEMATICAL analysis ,MATHEMATICAL physics - Abstract
The paper presents aspects that support the concepts of rationality and optimality in applied elasticity. It considers several ideas employed in optimal design from the classic intuitive perspective as well as from the modern computer based approaches. The original aspects of the paper consist of the general approach regarding the applied elasticity problems where the classic methods and the modern computer based methods must be equally considered in the design or evaluation of a structure. The presentation of the classical case studies use relevant figures and the computer based study employs an original and accurate FEM model which was calibrated by the use of experimental values. The next studies will consider different optimization algorithms employed to evaluate the extents of the applied elasticity hypotheses used in analytic models. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
14. APPLICATION OF GRAPH THEORY IN AUTOMATION.
- Author
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Zubac, Ivana, Rezic, Snjezana, and Glavas, Marijana Bandic
- Subjects
- *
GRAPH theory , *AUTOMATION , *COMPUTER algorithms , *ROBOTICS , *MATHEMATICAL analysis - Abstract
In many ways, engineering has always been dependent on mathematical background. This was usually mathematical analysis. In recent years, one of the areas of discrete mathematics - graph theory has been increasingly used in many fields, such as automation, programming or algorithms. In automatization process directed graphs are used for description and analysis of control system, where nodes represent states and arrows direct edges or transitions between states automaton that manages processes. In fact, as well as in other disciplines, automation for analysis and synthesis of control units are used in achievements of discrete mathematics. In this paper we show how to use graph to simplify the process of automation. We analyze the possibilities of using directed graphs for the purposes of analysis and synthesis of dynamic control system (elevator) with the aim of its simplification or minimization. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
15. MAPREDUCE-BASED FACE DETECTION IN IMAGES.
- Author
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Pinjuh, Ana, Vickovic, Linda, and Cavar, David
- Subjects
- *
IMAGE analysis , *BIOMETRIC identification , *DATABASES , *APPLICATION software , *MATHEMATICAL analysis - Abstract
Huge amounts of visual data have been generated daily on the Internet. Created data requires not only massive storage but also massive computational power for processing and analyzing data in efficient manner. Therefore, new distributed platforms like Hadoop are becoming more popular because of their capability to deal with huge amount of complex data in real time. MapReduce, a part of Hadoop, is frequently used programming model for writing distributed applications. This paper describes and presents results of MapReduce-based face detection process using Hadoop platform on BIOID image database. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
16. THE CONCEPTION OF A PROCESS COST CALCULATION.
- Author
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KOLOSOWSKI, ariusz and CHWASTYK, iotr
- Subjects
- *
ACTIVITY-based costing , *COST accounting , *COST estimates , *PRODUCT costing , *MATHEMATICAL analysis - Abstract
The issue of cost calculation of processes pursued in enterprise in the context of effective management of these processes has been carried out in the paper. The essence of process management and difficulties linked with measurement and improvement of processes in organizations have been described. Next the discussion concerns the imperfection of traditional methods of cost calculation. The cost calculation method based on Activity Based Costing has been proposed to enable precise processes cost determination together with its structure and continuous improvement of these processes. Finally, benefits and difficulties related to the implementation of the proposed method have been pointed out. [ABSTRACT FROM AUTHOR]
- Published
- 2012
17. INTERACTIVE SOFTWARE SYSTEM FOR MULTICRITERIA CHOOSING OF THE STRUCTURAL VARIANT OF COMPLEX TECHNICAL SYSTEMS.
- Author
-
MALAKOV, vo and ZAHARINOV, elizar
- Subjects
- *
COMPUTER software , *MULTIDISCIPLINARY design optimization , *DECISION making , *MATHEMATICAL analysis , *COMPUTER systems - Abstract
The choosing of a structural variant, is one of the main problems solved during the design process of complex technical systems. The real world conditions demand this choice to be made, on the basis of a set of criteria, which in the general case are conflicting. In the present paper are given the results, from the development of an interactive software system for multicriteria optimization, aiding the designers of technical products, during the decision making process of choosing of a structural variant. While developing the software system, the specifics of the problem have been taken into account. An effort has been made, for avoiding the disadvantages of similar, already known software systems. The application of the development is illustrated with a solved example. [ABSTRACT FROM AUTHOR]
- Published
- 2012
18. SCREENING ALEXANDRIA PORT SIMULATION MODEL BY USING SEQUENTIAL BIFURCATION PROCEDURE.
- Author
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Ragheb, M., Rekab, K., and Tadj, L.
- Subjects
SIMULATION methods & models ,MATHEMATICAL models ,MATHEMATICAL sequences ,BIFURCATION theory ,MATHEMATICAL analysis - Abstract
Screening simulation experiments is intended to eliminate unimportant factors from a simulation model. It usually results in a short list of important factors, so that effort may be concentrated upon this list. Sequential bifurcation (SB) procedure, developed by Bettonvil and Kleijnen [1], is a screening method that has proved to be efficient and effective. In this study, the SB procedure is used to determine the most important factors of the port of Alexandria, Egypt simulation model. Sixteen out of 44 factors are considered important. In addition, Cioppa [2] procedure is used to verify that the assumed unimportant factors by the SB procedure are really unimportant. This procedure is used to confirm that the suspected non-influential (unimportant) factors do not significantly affect the response output of interest. This procedure emphasized that the set of unimportant factors determined by the SB procedures is really unimportant. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
19. PREDICTION OF CUTTING FORCES IN THE DRY MACHINING OF LIGHTS ALLOYS.
- Author
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Domingo, R., Alvarez, R., and Sebastian, M. A.
- Subjects
CUTTING (Materials) ,MACHINING ,METAL cutting ,LIGHT metal alloys ,LENGTH measurement ,MATHEMATICAL analysis ,MANUFACTURING processes ,METALWORK ,METALWORKING industries - Abstract
This paper analyses the relationship between the cutting forces and length, according to experimental results obtained in lights alloys, in particular UNS A97050-T7, UNS A92024-T3, during the dry drilling. The tests have been performed with several cutting speed, 83 m/min, 60 m/min and 50 m/min. Box-Cox transformations have allowed finding a fitted model and determining a significant relationship between maximum cutting forces, for each hole, and cutting length. Thus, it is possible to establish prediction limits for new observations of cutting forces, at 95% confidence level. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
20. A TRANSFER MATRIX METHOD FOR STUDY OF VIBRATIONS OF PLANE BARS SYSTEMS.
- Author
-
Boiangiu, M. and Alecu, A.
- Subjects
TRANSFER matrix ,VIBRATION (Mechanics) ,STRUCTURAL frames ,FINITE element method ,MATRICES (Mathematics) ,BARS (Engineering) ,STRUCTURAL engineering ,STRUCTURAL analysis (Engineering) ,MATHEMATICAL analysis - Abstract
In this paper we study the simultaneous vibrations of bars systems, considering as been continuous medium. We obtained for the transfer matrix method because the finite elements method introduces specific features. We divide the system in cycles and we apply the transfer matrix method associated with transit matrix method for each cycle. We develop the free vibrations cases. We apply the purposed method to the concrete cases of a statically determinate system and of two statically indeterminate systems. The method can be applied associated with the graph theory, for identifying the cycles and the types of nodes. The method is indicated to be used in computational engineering, especially for the complicated bars systems. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
21. WHITE-SPACE DETECTION TECHNIQUES BASED ON NEIGHBORHOOD DISTANCE MEASUREMENTS.
- Author
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Boiangiu, C. A., Cananau, D. C., Dvornic, A. I., and Spataru, A. C.
- Subjects
AUTOMATIC extracting (Information science) ,INFORMATION filtering ,CONTENT-based image retrieval ,COMPUTER fonts ,FONTS & typefaces ,PRINTING ,TYPE measurements ,COMPUTER algorithms ,MATHEMATICAL analysis - Abstract
The purpose of this paper is to present a model for white space separators detection by using simple mathematical algorithms based on distances or font measure. The algorithms present new features as they are independent of the position in page, but they start from common ideas and improve them in order to obtain a satisfactory output. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
22. A CONCEPTUAL DESIGN APPLICATION BASED ON A NEW GENERALIZED ALGORITHM.
- Author
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Neagoe, M., Diaconescu, D., Jaliu, C., and Saulescu, R.
- Subjects
COMPUTER algorithms ,ELECTRICAL engineering ,MECHANICAL engineering ,MOTORS ,POWER (Mechanics) ,POWER transmission ,ROTATIONAL motion ,MATRICES (Mathematics) ,MATHEMATICAL analysis - Abstract
Based on a new algorithm variant of the conceptual design modeling, proposed by the authors, an application of this algorithm is analyzed on a product of motor - planetary reducer type. According to the new variant, the paper exemplifies the generation of the reducer solving structural variants and the reducer concept establishment. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
23. FRICTIONAL CONTACT PROBLEMS SOLVED BY NUMERICAL METHODS.
- Author
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Pop, N. and Cioban, H.
- Subjects
NEWTON-Raphson method ,ITERATIVE methods (Mathematics) ,FRICTION ,MECHANICAL engineering ,NONLINEAR statistical models ,MATHEMATICAL statistics ,NONLINEAR control theory ,NUMERICAL analysis ,MATHEMATICAL analysis - Abstract
The theory of non-smooth analysis shows that many results of standard analysis may be extended to a more general, non-smooth framework. In this paper we present some definitions and results from non-smooth analysis which leads to some sufficient conditions such that the nonlinear and non-differential system that modeling the contact problems with frictions, does have one solution, obtained by Newton's method using the generalized gradient. An example illustrating the generalizations by means of Newton's method applied to the contact problem with friction is presented. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
24. POSSIBILITIES THE ROLLING REDUCTION BY REFERENCING DIRECTION WITH SUSPENSION CORRELATION.
- Author
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Thierheimer, W. W., Tane, N., Thierheimer, D. C., and Ardeleanu, D.
- Subjects
MECHANICAL engineering ,STATISTICAL correlation ,REGRESSION analysis ,CURVILINEAR coordinates ,AUTOMOBILE steering gear ,AUTOMOBILE wheels ,MATHEMATICAL models ,MATHEMATICAL statistics ,MATHEMATICAL analysis - Abstract
In this paper, the important error induced by wheel suspending mechanism from rolling movement is reduced by means of solution proposed. This particular case we considered the elements that have big influence in dynamic behavior of the automotive, such as: steering geometry, the particular aspects regarding constructive solution. The problem of kinematical, dynamical and mathematical models is considered to characterize the dynamical behaviour of vehicles on curvilinear movement. The theoretical and experimental data comparison confirms with good accuracy the hypothesis made on the study of vehicle's stabilization system. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
25. SINGLE SOURCE FACILITY LOCATION PROBLEM USING GENETIC ALGORITHM.
- Author
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Lai, K. T., Luong, L. H. S., and Marian, R. M.
- Subjects
GENETIC algorithms ,OPTIMAL designs (Statistics) ,EXPERIMENTAL design ,CHROMOSOMES ,COMBINATORIAL optimization ,MATHEMATICAL optimization ,PROBLEM solving ,INFORMATION technology ,MATHEMATICAL analysis - Abstract
Single source capacitated facility location problems (SSCFLP) are basic location-allocation models used in the optimal design of supply chain, computer network and transmission power, amongst others. While genetic algorithm (GA) has been successfully applied to many combinatorial optimization problems, it has limited success when applied to solving SSCFLP. This paper proposes a GA solution which adopts an integer-based chromosome encoding approach using roulette wheel selection to allocate the alleles in the chromosome. A case study is conducted which shows that the algorithm is capable of solving the problem within short computational time. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
26. THE WEARING OUT COMPENSATION OF DIESEL ENGINES COMBUSTION CHAMBERS.
- Author
-
Ostoia, D., Negoitescu, A., and Tokar, A.
- Subjects
DIESEL motors ,INTERNAL combustion engines ,MECHATRONICS ,MECHANICAL engineering ,MICROELECTRONICS ,COMBUSTION chambers ,GEOMETRY ,GEOMETRIC modeling ,MATHEMATICAL analysis - Abstract
This paper presents a method for wearing out compensation in diesel engines combustion chambers through mechatronics systems implementation. The connection between geometrical combustion diesel engine parameters which also shape the level of wear and the engine parameters can be realized by the Electronic Central Unit (ECU). The Electronic Central Unit can correlate the existent changes by realizing the connection between combustion chamber pressure and geometrical changes due to wearing out and command the engine actuators with the newer values that describe the diesel engine working conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
27. THE INFLUENCE OF WELDING PARAMETERS ON TEMPERATURE DISTRIBUTION IN CASE OF EBW.
- Author
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Grecu, L., Demian, G., Demian, M., and Grecu, V.
- Subjects
MATHEMATICAL analysis ,NUMERICAL analysis ,ELECTRON beam welding ,INDUSTRIAL applications of electron beams ,METALWORK ,MANUFACTURING processes ,IRONWORK ,APPLICATION software ,MATHEMATICAL models - Abstract
This paper presents a mathematical and numerical model for the temperature distribution into a workpiece during electron beam welding (EBW). The mathematical modeling is based on the heat equation and on the specific phenomena that arise whenever the electron beam interferes with the matter, like the penetration of the electrons into the target. A MathCAD application developed on the mathematical and numerical model proposed is used to study the influence of the welding variables, such as the accelerating voltage, beam power and beam radius, as well as the material characteristics on the temperature field. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
28. THE SOFTWARE APPLICATION FOR MATHEMATIC DESCRIPTION OF EXTRACTION PROCESS COURSE.
- Author
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Charvatova, H., Janacova, D., Fialka, M., and Kolomaznik, K.
- Subjects
COMPUTER software ,APPLICATION software ,EXTRACTION (Chemistry) ,EXTRACTION techniques ,SOLID-liquid interfaces ,INTERFACES (Physical sciences) ,MATHEMATICAL models ,MATHEMATICAL analysis ,PHYSICAL & theoretical chemistry - Abstract
Many technological operations are based on a process of undesirable components removing from the solid material to the liquid phase. For propose of an optimal course of these components extraction, the physico-chemical formulation of the process is necessary to know. In the paper we deal with making of the software application of the removed component concentration field in the solid phase calculation during the extraction process. The calculation is based on analytical solution of the mathematical model of extraction process. We visualized the formatted dependence of the removing component concentration in the solid phase on the operating time in 2D and 3D projection for both real and dimensionless variables. We tested the application functions by calculation of course of extraction process - deliming. The obtained values we verified by laboratory experiments. The application will be used for description of other extraction processes courses. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
29. DYNAMIC SIMULATIONS OF A PLANETARY CHAIN SPEED INCREASER FOR R.E.S.
- Author
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SAULESCU, Rathi, DIACONESCU, Dorin, JALIU, Codnita, and VATASESCU, Monica
- Subjects
- *
MATHEMATICAL analysis , *SIMULATION methods & models , *OPERATIONS research , *SYSTEMS engineering , *COMPUTER software , *MATHEMATICAL models , *DYNAMICS , *NUMERICAL analysis - Abstract
The dynamic model of a planetary chain increaser used in small hydro is presented in this paper. The dynamical aspects presented in (Saulescu et al, 2009) represent the basics for the dynamic model presented in this paper. The dynamic response is obtained by means of Matlab-Simulink software. [ABSTRACT FROM AUTHOR]
- Published
- 2009
30. ON THE DYNAMIC MODELLING OF A PLANETARY CHAIN SPEED INCREASER FOR R.E.S.
- Author
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SAULESCU, Rathi, JALIU, Codnita, NEAGOE, Mircea, and VATASESCU, Monica
- Subjects
- *
MATHEMATICAL models , *SIMULATION methods & models , *DYNAMICS , *KINEMATICS , *ANALYTICAL mechanics , *MATHEMATICAL analysis , *NUMERICAL analysis , *FORCE & energy , *MECHANICS (Physics) - Abstract
The dynamic model of a planetary chain increaser used in small-hydros is presented in this paper. The paper approaches the appropriate structural, kinematical and dynamical aspects; the presented relations are going to be used during the dynamic modelling of the increaser. [ABSTRACT FROM AUTHOR]
- Published
- 2009
31. GENETIC ALGORITHMS MULTI-OBJECTIVES OPTIMISATION OF NONSTANDARD SPUR GEARS.
- Author
-
CHIRA, Flavia, BANICA, Mihai, and BUTNAR, Lucian
- Subjects
- *
GENETIC programming , *COMBINATORIAL optimization , *COMBINATORICS , *GENETIC algorithms , *MATHEMATICAL optimization , *EXPERIMENTAL design , *OPERATIONS research , *MATHEMATICAL analysis - Abstract
The paper present a method for optimal design of non-standard spur gears, with the aim of minimising multi-objectives optimisation functions, obtained by weighted sum of different evaluation function, represented of the significant values of some functional parameters. Those parameters can be carrying out with designing and analysing computer applications. The paper is focused on using original MATLAB application, based on genetic algorithms, developed for optimal design, with the aim of simultaneous minimising the contact stress and bending stress on the pinion and on the gear, of asymmetric gears. Having asymmetrical involutes teeth profiles, asymmetric gears are non-standard gears obtained with the "direct gear design method", used for improving the performances of the involutes toothed gears. [ABSTRACT FROM AUTHOR]
- Published
- 2009
32. NUMERICAL MODELING OF MICRO-CRACK PROPAGATION IN COMPOSITES.
- Author
-
Majer, Zdenek
- Subjects
- *
NUMERICAL analysis , *MATHEMATICAL analysis , *NONLINEAR statistical models , *FINITE element method , *PARTICLES - Abstract
The main objective of this paper is the numerical investigation of fracture behaviour in polymeric particulate composite with rigid particles. This article is focused on estimation of next micro-crack propagation in nonlinear matrix. The composite is modelled as a three-phase continuum and using finite element method is solved. The interaction of micro-crack and particles covered by the interphase is analyzed. [ABSTRACT FROM AUTHOR]
- Published
- 2011
33. GRAPHICAL INTERPRETATIONS FUNCTIONS OF SEVERAL VARIABLES FOR USING IN THE TECHNOLOGICAL EXPERIMENTS.
- Author
-
Macura, Dusan
- Subjects
- *
GRAPHIC methods , *MATHEMATICAL analysis , *TECHNOLOGICAL innovations , *RESEARCH & development , *PREDICTION models , *MANUFACTURING processes , *PRODUCTION engineering - Abstract
In the paper behaviou of a function present graphs of a functions by using mathematical analysis and graphical methods that include plotting points and determined symmetry. These techniques are adequate for obtaining a graph. We can use properties of the functions to predict some parameters of he technological experiments for example the height and speed of the manufacturing. The presentation functions are inspirative and motivated for the manufacturing experiments. We study important geometric properties of the curves. [ABSTRACT FROM AUTHOR]
- Published
- 2011
34. ANALYSIS AND OPTIMIZATION OF JUNCTION STRUCTURES MADE FROM LAYERED COMPOSITES USING FEA.
- Author
-
Tudor, D. I., Vlasceanu, D., Dinu, G., and Petrescu, H. A.
- Subjects
- *
MATHEMATICAL optimization , *FINITE element method , *SEMICONDUCTOR junctions , *COMPOSITE materials , *MATHEMATICAL analysis - Abstract
This paper highlights analysis and optimization method of junction layered composites structures using finite elements analysis (FEA). In practice, there are many junction structures made from alloy or composite materials. The authors was effectuated a study for one type of structures made from layered composites material namely a junction between a tube and a flange. The optimization process was accomplished in two steps: the first step was the static analysis of the structure and the second step was the optimization process aiming at the weight reduction of the entire structures. [ABSTRACT FROM AUTHOR]
- Published
- 2010
35. IMPROVEMENT OF WINDMILL ASSEMBLY PROCESS WITH FMEA.
- Author
-
Prostean, G., Tamasila, M., and Taucean, I. M.
- Subjects
- *
WINDMILL design & construction , *LEAN management , *MANUFACTURING processes , *MATHEMATICAL analysis , *PRODUCTION engineering - Abstract
The paper present the effects of change of lean manufacturing implementation in a company focusing on following objective: to synthesis all involved procedures, stages and instruments, to draw up a FMEA table for a real case study (a windmill farm), to measure the efficacy, efficiency for cell versus line manufacturing. [ABSTRACT FROM AUTHOR]
- Published
- 2010
36. THE NEW STERN DESIGN - A SOLUTION OF DRAG REDUCTION OF SHIPS.
- Author
-
Ali, B. and Bejan, M.
- Subjects
- *
NAVAL architecture , *SHIPBUILDING , *NUMERICAL analysis , *MATHEMATICAL analysis , *NUMERICAL solutions to biharmonic equations , *NUMERICAL solutions to the Cauchy problem - Abstract
The paper presents an original stern shape design. It leads to a better fluid flow, which reduces the drag. There are presented the direct and reverse problems and the numerical implementation. A current tube is taken into consideration. It contains the propeller, extends towards the prow and includes the entire stern section of a classic hull. The dynamics of a propeller depends on environment system. The fluid flow around a propeller working on a ship is different to that one tested in free water or in a cavitation tunnel. The fluid flow near the stern is a key factor for the ship design. The consequence is that a new stern design is a solution of drag reduction of ships. [ABSTRACT FROM AUTHOR]
- Published
- 2010
37. PERFORMANCE EVALUATION OF A FLEXIBLE MANUFACTURING SYSTEM USING TIMED PETRI NETS.
- Author
-
COMAN, Daniela and IONESCU, Adela
- Subjects
- *
PETRI nets , *PERFORMANCE , *NETS (Mathematics) , *GRAPH theory , *KEY performance indicators (Management) , *PERFORMANCE standards , *MATHEMATICAL analysis , *MATHEMATICS , *DYNAMICS - Abstract
Designing a manufacturing system requires modelling and performance evaluation techniques. To support this, a modelling method based on timed Petri nets is presented in this paper. A graphic construction of the net is achieved; transporting it into a specific mathematical formalism it is made, so that the fulfilled structure to be fully retrieved and used to bring out the internal dynamics of the model. The timed Petri net model is implemented in Petri Net Toolbox under MATLAB environment. There are determined the global performance indicators in order to evaluate the performance of the considered flexible manufacturing system. [ABSTRACT FROM AUTHOR]
- Published
- 2009
38. COMPLEXITY CLASSES FOR MULTI-VARIABLE COMPLEXITY FUNCTIONS.
- Author
-
MOGOS, Andrei - Horia and FLOREA, Adina Magda
- Subjects
- *
ALGORITHMS , *MATHEMATICAL functions , *COMPUTATIONAL complexity , *MATHEMATICAL variables , *MATHEMATICS , *DIFFERENTIAL equations , *MATHEMATICAL analysis , *CALCULUS , *EQUATIONS - Abstract
The complexity of an algorithm is usually expressed using complexity functions and complexity classes, in this paper we present a method to reduce the work with multi-variable complexity functions to the work with one-variable complexity functions. We define five complexity classes for multi-variable complexity functions and then we prove some properties for these classes. [ABSTRACT FROM AUTHOR]
- Published
- 2009
39. COMPUTING OF STRESS INTENSITY FACTOR USING J-INTEGRAL METHOD WITH F.E.A.
- Author
-
TIEREAN, Mircea and BALTES, Liana
- Subjects
- *
FRACTURE mechanics , *DEFORMATIONS (Mechanics) , *STRENGTH of materials , *ELASTIC solids , *MECHANICS (Physics) , *MATHEMATICAL analysis - Abstract
This paper presents a method to calculate the stress intensity factor using in the J-integral method. After the explanation of theoretical aspects, an application using two different F.E.A. programs is solved to illustrate feasibility of the method. The results obtained using F.E.A. are similar to those obtained with the analytical method. [ABSTRACT FROM AUTHOR]
- Published
- 2009
40. THE DETERMINATION OF THE STRAIN STATE IN THE BED OF A PRESS.
- Author
-
GHEORGHIU, Horia, DINU, Gabriela, and BACTU, Florin
- Subjects
- *
FINITE element method , *CAD/CAM systems , *COMPUTERS in production management (Manufacturing) , *ELECTRONIC equipment , *NUMERICAL analysis , *MATHEMATICAL analysis - Abstract
The paper presents a numerical determination of the strain state in a structure using the finite element method. The omputation results were compared with the ones obtained using experimental measurements with electric transducers. The aim of this work was to determine the strain state in the bed of a press for curing the component elements of a rubber belt with a metallic insertion. [ABSTRACT FROM AUTHOR]
- Published
- 2009
41. THE EFFICIENCY OF A NEW GREEDY HEURISTIC FOR SOLVING PERMUTATION FLOWSHOP SCHEDULING PROBLEM.
- Author
-
ANCAU, Mircea
- Subjects
- *
PRODUCTION scheduling , *MATHEMATICAL optimization , *PRODUCTION control , *ALGORITHMS , *PERMUTATIONS , *COMBINATORICS , *HEURISTIC , *PROBLEM solving , *MATHEMATICAL analysis - Abstract
This paper presents an original greedy constructive algorithm for solving the permutation flowshop scheduling problem with makespan optimization criterion. The algorithm starts with a pair ofjobs chosen based on optimization criterion and adds every new job to the schedule by means of a greedy selection procedure. Expansive computational experiments indicate that, concerning the quality of solutions, selective greedy heuristic performs almost as well as NEH algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2009
42. OPTIMAL CONTROL PROBLEM IN NEW PRODUCTS LAUNCH.
- Author
-
DOBOCA, Corina
- Subjects
- *
NEW product development , *PRODUCT management , *PRODUCT launches , *CONTROL theory (Engineering) , *AUTOMATION , *MATHEMATICAL analysis , *MAXIMUM principles (Mathematics) , *NUMERICAL solutions to partial differential equations , *MACHINE theory - Abstract
This paper solve a problem of optimal control with fixed limits using The Pontreaguine Maximum Principle. (Pontreaguine, 1974) This problem is modelling in mathematical way the new products launch. The order of these two control functions application conduce to two minimum strokes. Therefore we have the possibility to choose the smallest one. [ABSTRACT FROM AUTHOR]
- Published
- 2009
43. MODELING AND SIMULATION OF AN OUTPUT ELECTRIC CURRENT FROM A FLUX COMPRESSION GENERATOR COIL.
- Author
-
DOBREF, Vasile, SOTIR, Alexandru, TARABUTA, Octavian, and VLADU, Gabriel
- Subjects
- *
SIMULATION methods & models , *ELECTRIC currents , *MAGNETOHYDRODYNAMICS , *MATHEMATICAL analysis , *MATHEMATICAL models , *COMPTON effect , *NUMERICAL analysis , *NUCLEAR explosions - Abstract
The present technology used for the generation of an electromagnetic pulse (EMP) in defence applications has been implemented starting with three sorts of generators so far: flux compression generators (FCG), magneto-hydrodynamic (MHD) generators and virtual cathode oscillators (VCO). This paper describes the basic principles of the most common and effective type of generator, the FCG and particular results obtained by a research team of the Romanian naval academy during designing and building an electromagnetic bomb prototype. As the FCG requires a coil, the authors present hereinafter the preliminary calculations of the output current that have been used in the actual design. All the results presented hereby have been demonstrated by the actual prototype developed. [ABSTRACT FROM AUTHOR]
- Published
- 2009
44. TECHNIQUES OF OBTAINING GEOMETRIC MODELS.
- Author
-
v, Cristian, CIOANA, Cristian, STAN, Daniel, and ICLANZAN, Tudor
- Subjects
- *
MATHEMATICAL models , *COMPUTER-aided design , *REVERSE engineering , *COMPUTER-aided engineering , *NUMERICAL analysis , *MATHEMATICAL analysis , *METHODOLOGY - Abstract
The paper describes the implementation of a two method in which an initial CAD model is updated from a physical model. To obtain a geometric model from an existing physical model relatively complex and for which there is no technical documentation we will present two methods - reverse engineering and 3D sketch. [ABSTRACT FROM AUTHOR]
- Published
- 2009
45. NUMERICAL ANALISYS OF DISCONTINUITIES IN BEAM STRUCTURES.
- Author
-
STAN, Florina, GROZEA, Marius - Alexandru, DOBRESCU, Corina, HADAR, Anton, and CONSTANTINESCU, Ioan
- Subjects
- *
NUMERICAL analysis , *CONFIGURATION space , *FINITE element method , *MATHEMATICAL analysis , *CAD/CAM systems , *CALCULUS , *INFINITESIMAL geometry , *MATHEMATICAL functions , *DIFFERENTIAL equations - Abstract
This paper presents specific aspects of the beam structures junctions nonlinear calculus. The substructuring method applied with the help of some high-performance numerical methods is considered the only way to study some high level stress zones. The working methodology has an original character and may be generalized to all structures with geometrical and material discontinuities. The stress state configurations obtained using the finite element method allow a correct evaluation of the safety coefficients and reliability of the analyzed structure. [ABSTRACT FROM AUTHOR]
- Published
- 2009
46. INSTRUMENTED IMPACT TESTING OF CFRP COMPOSITE LAMINATED PLATES.
- Author
-
DOGARU, Florin and UDROIU, Razvan
- Subjects
- *
COMPOSITE materials , *EPOXY compounds , *NUMERICAL analysis , *ESTERS , *MINDLIN theory , *MATHEMATICAL models , *MATHEMATICAL analysis - Abstract
CFRP laminated composite plates subjected to low velocity impact have been investigated in this paper using an instrumented drop-weight test device. For response parameters evaluation of the low velocity impact test a simple block diagram using LabVJEW program is presented. The investigations was done on composite laminates plates carbon/epoxy vinyl ester made of symmetrical laminate with 8 unidirectional laminae and [01-451+45/90], stacking sequence, simply supported at the edges. [ABSTRACT FROM AUTHOR]
- Published
- 2009
47. 3D TOOL WEAR SIMULATION FOR TURNING PROCESS.
- Author
-
PATRASCU, Gabriela, CARUTASU, Nicoleta Luminita, and DRAGOMIRESCU, Cristian George
- Subjects
- *
SIMULATION methods & models , *OPERATIONS research , *MATHEMATICAL analysis , *SYSTEMS engineering , *MATHEMATICAL models , *NUMERICAL analysis - Abstract
This paper presents results obtained from computational simulation models for cutting process. The objective of the present study is to evaluate tool wear using simulation of mechanical cutting. The orthogonal cutting process has been simulated by the finite element code, explicit code DEFORM 3D. This software is a commercial code which contains a module developed especially for simulating mechanical metal cutting. [ABSTRACT FROM AUTHOR]
- Published
- 2009
48. USING FUZZY CONTROL SYSTEMS FOR MULTI-DISCIPLINARY DESIGN OPTIMIZATION OF SANDWICH PANELS.
- Author
-
VELEA, Marian Nicolae and LACHE, Simona
- Subjects
- *
FUZZY sets , *MATHEMATICAL optimization , *METHODOLOGY , *OPERATIONS research , *MATHEMATICAL analysis , *SIMULATION methods & models , *SYSTEM analysis - Abstract
Multi-disciplinary design optimization methods of sandwich structures have not been clearly established yet. in this paper, it is presented a method that uses a fuzzy control loop system to fit the individual components properties of a sandwich assembly to its overall properties or functional capabilities. The method may be useful in the primary stage of a sandwich panel design in order to reduce time and cost, providing useful information for further analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2009
49. THE SOLID MODEL OF THE DEFORMED FLEXIBLE GEAR OF THE HARMONIC DRIVE.
- Author
-
SERBAN, Remus Ioan
- Subjects
- *
HARMONIC drives , *PLANETARY gearing , *POWER transmission , *SPECIAL functions , *COMPUTER-aided design , *MATHEMATICAL analysis , *CONIC sections , *PLANE curves , *ELLIPSES (Geometry) - Abstract
The paper presents a method of designing a solid model of the deformed flexspline of a harmonic drive. The deforming curve was considered an ellipse. The purpose is to create a deformed flexspline with real positions of the teeth around the circumference of the flexspline. The technology for the model definition uses the program AutoCAD 2009, and involves two special functions: lofting and divide. [ABSTRACT FROM AUTHOR]
- Published
- 2009
50. ABOUT THE DYNAMIC STRESSES INDUCED BY THE VIBRATIONS OF AN ELECTRONIC CIRCUIT PLATE.
- Author
-
DRAGOMIRESCU, Cristian George, ILIESCU, Victor, and PATRASCU, Gabriela
- Subjects
- *
ELECTRONIC circuits , *ELECTRONIC circuit design , *ELECTRON tubes , *MATHEMATICAL analysis , *STRUCTURAL plates , *INFINITESIMAL geometry , *STRAINS & stresses (Mechanics) , *DYNAMICS , *MATHEMATICAL models - Abstract
The paper is analysing the dynamic stresses induced by the mechanical vibrations of an electronic circuit plate, considering the most usual situations dealt with in engineering practice. The corresponding calculi models are deduced and for one of these models the results of the experimental study carried out are presented and discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2009
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