The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Abstract An analytical model of circular contact spots was used in conjunction with numerical methods to estimate the impact electro-migration has on separable power contacts. A single spot model was developed using relative variables to estimate the rate of degradation. The single spot model was generalized to include variations in spot size and change in contact voltage and subsequently used to...
The possibility of the formalization of chess high level subjective concepts, such as: "beautiful mate", "unexpected move" and others is considered. To analyze these concepts the mathematical apparatus of fuzzy sets is applied and an acceptable correlation between computer and humans estimations of the "beautiful mate" for certain positions is demonstrated.
We propose a semi-phenomenological model to calculate the material gain of multiple quantum well broadband Semiconductor Optical Amplifier (SOA). We show that this proposed model permits to fit well the experimental results of a broadband SOA gain and noise figure over a range of 100nm.
The dynamic non-linear material response of graphene is introduced into finite-difference time-domain simulations using a carrier rate equation. Experimental measurements of grapheme's relaxation time and saturation intensity are used to demonstrate sub-picosecond pulse formation via passive mode-locking in a 95 μm long Bragg cavity.
This paper describes the effect of transmission backlash on web tension in roll-to-roll manufacturing systems and provides a method to mitigate this effect. The term web is used to refer to flexible materials which are manufactured and processed in a continuous form by transporting the material on rollers through processing machinery; this type of manufacturing is referred to as Roll-to-Roll (R2R)...
In this work, the regional level set is employed to track interfaces in multiphase fluid simulations, while considering the behavior of the film between distinct phases. Also, properties of each phase are tracked as they merge or split, and an algorithm to apply these operations is proposed. Furthermore, it is introduced a method to handle undesired volume changes that tries to minimize the total...
This article demonstrates the ability of on-line optimization of cone crushers, specifically maximization of the total throughput of the crusher by adjusting the eccentric speed (ω). The on-line optimization was based on the Extremum-Seeking Control (ESC) approach, which is advantageous when optimizing systems with unknown time varying characteristics. Two types of gradient based approaches are tested...
A scaled working policy and some special modelling tools/techniques are presented for the management of wide band interference problems on complex platforms, like IEMI (Intentional ElectroMagnetic Interference) or HIRF (High Intensity Radiated Field), in the frame of industrial processes.
This paper summarizes the results obtained from the design, creation and implementation of the Universal Model of Educational Process with the Support of Petri Nets. Based on the created educational models in Petri nets we are able to verify and simulate individual processes, which are carried out during the passage of student through the e-course in LMS. Universal model was gradually implemented...
This paper assesses the accuracy of a rectangular waveguide pierced by a tubular load sample holder for measuring liquid materials at high temperatures with a formulation based on Abdulnour's method. The measurement technique is derived from the transmission line method. The sample holder is adapted from a section of a rectangular waveguide pierced by a tubular load for high temperature measurements...
Ball grid array (BGA) has the characters of excellent heat dissipation and high mechanical strength to satisfy with the need of high density packaging of electro produces. However BGA faces some problems of complex viscoplastic deformation, difficult failure test and high repair cost. This paper establishes a complex multichip packaging module with lead-free solder ball SAC305 BGA solder ball based...
Compliant mechanisms have made an enormous contribution in the design process of various fields such as for adaptive structures, hand-held tools, components in transportations, electronics, and surgical tools. The use of compliant mechanisms will help in reducing the number of components, which therefore decrease manufacturing cost and additionally increase the performance. Topology optimization has...
Based on the finite element approach and the strain gradient (SG) theory, this paper produced a study on factors of size effect and minimum cutting thickness phenomenon in the micro-cutting process. Mechanisms of micro-cutting focusing on its characteristics that include size effect, tool edge radius and minimum cutting thickness has been studied. A new constitutive relationship based on SG theory...
The increasing requirements for heat dissipation in modern microelectronic devices makes it necessary to develop new materials (e.g. thermal interface materials) with high thermal conductivity. Due to excellent thermal and thermo-mechanical properties some nanomaterials, like carbon nanotubes, are increasingly being used to create new thermally conductive composites. The development of such composites...
This paper describes the simulation of the phenomenon of nucleation of the precipitate Al3Sc in an Aluminum Scandium alloy using the kinetic Monte Carlo (kMC) method and the density-based clustering with noise (DBSCAN) method to filter the simulation data. To conduct this task, kMC and DBSCAN algorithms were implemented in C language. The study covers a range of temperatures, concentrations, and dimensions,...
Stereoscopic Warehouse plays an important role in the modernization of the logistics field. It is characterized by an informatization, automation, high efficiency, and often used in regional distribution center. In some special occasions or due to special field, the stereoscopic warehouse must be with tandem storage space in the reason that putting all of the racks parallelly in a single storage requires...
The electrical conductivity in semiconductors vs. temperature (Mott's equation) can be described by some nonlinear functional equations of the transcendental type. In this paper, the problem of finding the exact analytical closed-form solution for Mott's equation is studied, in some detail, by the Special Trans Functions Theory — STFT. The numerical results and graphical presentations confirm validity...
ANSYS/LS-DYNA is employed to propose a finite element model of typical shaped charge jet generator and target structure. This model is calculated with the method of ALE algorithm and multi-material fluid-solid coupling. Results of numerical simulation for shaped charge jet penetrating into target are given, and a common method for numerical simulation for this kind of problem comes in to being.
Based on Held's critical initiation criterion of high speed fragment impacting the bare charge, the model for calculating critical initiation speed was proposed for the shelled explosive, the LS-DYNA method was used to simulate the initiation process of shelled explosive impacted by fragment. The results show that, the error of numerical simulation and theoretical calculation was very small, which...
The work described in this conference talk follows up recent work on the development of a test for lack of field emission orthodoxy. There are three stages of discussion involved. First, the results of applying the test to 17 selected published FN plots are reported. About half fail the test, showing that related published field enhancement factor (FEF) values are unreliable. In several cases, this...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.