scholarly journals Practical implementation of diode SPICE model with reverse recovery

Author(s):  
DENYS ZAIKIN

<div>This paper presents a way to generate the correct SPICE sub- circuit using only parameters from the manufacturer's diode datasheet. Characterization tool software was created and tested and is now freely available to download and use.</div>

2021 ◽  
Author(s):  
DENYS ZAIKIN

<div>This paper presents a way to generate the correct SPICE sub- circuit using only parameters from the manufacturer's</div><div>diode datasheet. Characterization tool software was</div><div>created and tested and is now freely available to</div><div>download and use.</div>


Author(s):  
Kapil Bhardwaj ◽  
Mayank Srivastava

Purpose This paper aims to develop a mathematical model for four-lobe memristor (FLM) element. The four-lobe memristive behaviour can be used in realization of hyperchaotic oscillators and implementation of multi-bit memories. For verification of the developed mathematical framework, two FLM circuit emulators have been presented using VDCC and IC LM13700, respectively. Design/methodology/approach A mathematical model for FLM has been developed in which, the condition for the existence of symmetrical four lobes, instances and coordinates of the end points of lobes has been derived and presented. Using this mathematical framework, a FLM emulator based on VDCC has been developed. To validate the possibility of practical implementation of FLM concept, an IC LM13700-based circuit has also been developed. The workability of VDCC based circuit has been verified by running simulations in PSPICE environment using CMOS VDCC model. Similarly, the behaviour of LM13700 IC-based circuit has been confirmed by SPICE model of LM13700 IC. Findings It has been shown mathematically that under certain conditions, third-order flux dependent equation of memductance can be used to generate four lobes on the transient v-i plane. Also, two FLM emulators without using any voltage multiplier circuit/IC have been reported. Originality/value From the best knowledge of the authors, there are no such FLM emulators that have been reported in literature so far, which operates at practical operating frequencies.


2021 ◽  
Author(s):  
DENYS ZAIKIN

<div>This paper presents a way to generate the correct SPICE sub- circuit using only parameters from the manufacturer's</div><div>diode datasheet. Characterization tool software was</div><div>created and tested and is now freely available to</div><div>download and use.</div>


Author(s):  
R. C. Gonzalez

Interest in digital image processing techniques dates back to the early 1920's, when digitized pictures of world news events were first transmitted by submarine cable between New York and London. Applications of digital image processing concepts, however, did not become widespread until the middle 1960's, when third-generation digital computers began to offer the speed and storage capabilities required for practical implementation of image processing algorithms. Since then, this area has experienced vigorous growth, having been a subject of interdisciplinary research in fields ranging from engineering and computer science to biology, chemistry, and medicine.


Author(s):  
C. C. Ahn ◽  
S. Karnes ◽  
M. Lvovsky ◽  
C. M. Garland ◽  
H. A. Atwater ◽  
...  

The bane of CCD imaging systems for transmission electron microscopy at intermediate and high voltages has been their relatively poor modulation transfer function (MTF), or line pair resolution. The problem originates primarily with the phosphor screen. On the one hand, screens should be thick so that as many incident electrons as possible are converted to photons, yielding a high detective quantum efficiency(DQE). The MTF diminishes as a function of scintillator thickness however, and to some extent as a function of fluorescence within the scintillator substrates. Fan has noted that the use of a thin layer of phosphor beneath a self supporting 2μ, thick Al substrate might provide the most appropriate compromise for high DQE and MTF in transmission electron microcscopes which operate at higher voltages. Monte Carlo simulations of high energy electron trajectories reveal that only little beam broadening occurs within this thickness of Al film. Consequently, the MTF is limited predominantly by broadening within the thin phosphor underlayer. There are difficulties however, in the practical implementation of this design, associated mostly with the mechanical stability of the Al support film.


Author(s):  
Molla Asmare ◽  
Mustafa Ilbas

Nowadays, the most decisive challenges we are fronting are perfectly clean energy making for equitable and sustainable modern energy access, and battling the emerging alteration of the climate. This is because, carbon-rich fuels are the fundamental supply of utilized energy for strengthening human society, and it will be sustained in the near future. In connection with this, electrochemical technologies are an emerging and domineering tool for efficiently transforming the existing scarce fossil fuels and renewable energy sources into electric power with a trivial environmental impact. Compared with conventional power generation technologies, SOFC that operate at high temperature is emerging as a frontrunner to convert the fuels chemical energy into electric power and permits the deployment of varieties of fuels with negligible ecological destructions. According to this critical review, direct ammonia is obtained as a primary possible choice and price-effective green fuel for T-SOFCs. This is because T-SOFCs have higher volumetric power density, mechanically stable, and high thermal shocking resistance. Also, there is no sealing issue problem which is the chronic issues of the planar one. As a result, the toxicity of ammonia to use as a fuel is minimized if there may be a leakage during operation. It is portable and manageable that can be work everywhere when there is energy demand. Besides, manufacturing, onboard hydrogen deposition, and transportation infrastructure connected snags of hydrogen will be solved using ammonia. Ammonia is a low-priced carbon-neutral source of energy and has more stored volumetric energy compared with hydrogen. Yet, to utilize direct NH3 as a means of hydrogen carrier and an alternative green fuel in T-SOFCs practically determining the optimum operating temperatures, reactant flow rates, electrode porosities, pressure, the position of the anode, thickness and diameters of the tube are still requiring further improvement. Therefore, mathematical modeling ought to be developed to determine these parameters before planning for experimental work. Also, a performance comparison of AS, ES, and CS- T-SOFC powered with direct NH3 will be investigated and best-performed support will be carefully chosen for practical implementation and an experimental study will be conducted for verification based on optimum parameter values obtained from numerical modeling.


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 ◽  
pp. 65-72
Author(s):  
V. V. Savchenko ◽  
A. V. Savchenko

This paper is devoted to the presence of distortions in a speech signal transmitted over a communication channel to a biometric system during voice-based remote identification. We propose to preliminary correct the frequency spectrum of the received signal based on the pre-distortion principle. Taking into account a priori uncertainty, a new information indicator of speech signal distortions and a method for measuring it in conditions of small samples of observations are proposed. An example of fast practical implementation of the method based on a parametric spectral analysis algorithm is considered. Experimental results of our approach are provided for three different versions of communication channel. It is shown that the usage of the proposed method makes it possible to transform the initially distorted speech signal into compliance on the registered voice template by using acceptable information discrimination criterion. It is demonstrated that our approach may be used in existing biometric systems and technologies of speaker identification.


Author(s):  
N. I. Pak ◽  
E. V. Asaulenko

The relevance of the study under consideration is due to the need to increase the efficiency of students independent work in solving computational problems. A theoretical rationale is proposed and the practical implementation of an automated training and diagnostic system for the formation of skills to solve problems according to the “white box” model is described. The leading idea of the study is the construction of mental schemes for a given topic, which allow to visualize the dynamics of changes in the learner’s level of ability to solve computational problems. The methods of accounting for forgetting educational information and methods of personalized selection of tasks are substantiated. The site for self-management of user independent work is available at the link: http://msbx.ru. The materials of the article are of practical value for teachers who use e-learning tools in the educational process.


Author(s):  
Galyna Moroz

Purpose. The article is aimed at analyzing the general theoretical principles and the essential characteristics of legal restrictions in environmental law; defining category of “environmental legal restrictions”, their content, system and the status of the respective legislation. Methodology. The methodology consists in carrying out a comprehensive analysis of the provisions of environmental legislation and formulating relevant conclusions on this basis. During the research, the following methods of scientific research were used: terminological, systemic and structural, comparative legal, structural and functional. Results. The objectively determined necessity of unconditional adherence to the legally established environmental requirements, prohibitions and restrictions as well as their potential scientifically substantiated enhancement in order to achieve environmentally significant goals oriented towards the priorities of sustainable development is substantiated. Restrictive mechanisms are scattered across statutory and regulatory acts of different legal force and even different branches of law, therefore, the need for their systematization and unification as well as generalization of the experience of their practical implementation in order to establish a comprehensive system of environmental restrictions is discussed. In our opinion, the conceptual basis and general essential characteristics of public environmental requirements and restrictions should be reflected in the future Environmental Code of Ukraine. Scientific novelty. In the course of the research, the author defines restrictions in environmental law as a specific sectoral imperative mechanism for regulating relations in the field of environmental safety, which consists in systematically introducing legislation on imperative provisions of environmental law as well as establishing specific legal regimes and mechanisms for their application and implementation. Practical significance. The main conclusions can be used in law-making and law-enforcing activities, as well as in further theoretical and legal research and in the educational process.


Sign in / Sign up

Export Citation Format

Share Document