Computer modeling of parametric converters with frequency and phase control

2020 ◽  
pp. 96-106
Author(s):  
В.В. Иванов ◽  
Я.В. Еремина ◽  
С.В. Ермолова
Keyword(s):  
Mathematical Modeling ◽  
Computer Modeling ◽  
Digital Filters ◽  
High Sensitivity ◽  
Frequency Stability ◽  
Phase Control ◽  
Operational Parameters ◽  
Conversion Characteristic ◽  
Aerospace Systems ◽  
Stability And Accuracy

Осуществлено математическое моделирование параметрических преобразователей, использующих режим повышенной чувствительности. Названный режим преобразователей позволяет повысить эксплуатационные показатели аппаратуры авиационно-космических систем. Показано, что преобразователи с фазовым управлением обладают линейными характеристиками и являются более перспективны. Применение в них цифровых фильтров ведет к повышению стабильности частоты и точности настройки, а также минимизируется погрешность характеристики преобразования. Mathematical modeling of parametric converters using high-sensitivity mode is carried out. The named mode of converters allows to increase operational parameters of the equipment of aerospace systems. It is shown that phase-controlled converters are more promising because they have linear characteristics and allow the use of digital filters, which leads to an increase in frequency stability and accuracy of adjustment, and also minimizes the error of the conversion characteristic.

Design of the High-Speed X-Band Frequency Hopping Source

2014 ◽  
Vol 662 ◽  
pp. 231-234
Author(s):  
Shuang Zhao ◽  
Dian Ren Chen
Keyword(s):  
High Speed ◽  
Frequency Hopping ◽  
Frequency Stability ◽  
Band Frequency ◽  
X Band ◽  
Frequency Source ◽  
The Stability ◽  
Stability And Accuracy ◽  
Low Phase Noise ◽  
Communication Equipment

In modern communication system, the spacing of channel becomes ever more finely. For communication equipment, it has made ​​high demands on the stability and accuracy of the frequency. Based on DDS technology, combined with the multiplier circuit, we developed a high-speed X-band frequency hopping source. Experimental results show that this frequency source is with excellent frequency stability and low phase noise.

Applied Problems of Marine Mechanical Systems Technical Condition Estimation

2017 ◽  
Author(s):  
Неменко ◽  
Aleksandra Nemenko ◽  
Никитин ◽  
Mihail Nikitin
Keyword(s):  
Mathematical Modeling ◽  
Time Series ◽  
Mechanical Systems ◽  
Technical Condition ◽  
Technical Diagnostics ◽  
Operational Parameters ◽  
Physical Processes ◽  
Minimum Loss ◽  
Condition Estimation

We consider the problems of technical diagnostics of marine mechanical systems such as machinery and other mechanisms. We propose effective techniques of mathematical modeling concerning physical processes during operation of these systems, machines and mechanisms. We describe algorithms of time series far forecast for operational parameters, ways of time series composition with minimum loss of accuracy and application of all of this for the prevention of breakdowns and other accidents.

Development of an Indirect Competitive Enzyme-Linked Immunosorbent Assay Based on the Multiepitope Peptide for the Synchronous Detection of Staphylococcal Enterotoxin A and G Proteins in Milk

2015 ◽  
Vol 78 (2) ◽  
pp. 362-369 ◽  
Author(s):  
MINGYAN LIANG ◽  
TINGTING ZHANG ◽  
XUELAN LIU ◽  
YANAN FAN ◽  
SHENGLIN XIA ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Food Poisoning ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Synchronous Detection ◽  
Standard Curve ◽  
Stability And Accuracy

Staphylococcal food poisoning (SFP), one of the most common foodborne diseases, results from ingestion of staphylococcal enterotoxins (SEs) in foods. In our previous studies, we found that SEA and SEG were two predominant SE proteins produced by milk-acquired S. aureus isolates. Here, a tandemly arranged multiepitope peptide (named SEAGepis) was designed with six linear B-cell epitopes derived from SEA or SEG and was heterologously expressed. The SEAGepis-specific antibody was prepared by immunizing rabbit with rSEAGepis. Then, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) based on rSEAGepis and the corresponding antibody was developed to simultaneously detect SEA and SEG. Under the optimized conditions, the ic-ELISA standard curve for rSEAGepis was constructed in the concentration range of 0.5 to 512 ng/ml, and the average coefficients of variation of intra-and interassay were 4.28 and 5.61% during six standard concentrations. The average half-maximal inhibitory concentration was 5.07 ng/ml, and the limit of detection at a signal-to-noise ratio of 3 was 0.52 ng/ml. The anti-rSEAGepis antibody displayed over 90% cross-reactivity with SEA and SEG but less than 0.5% cross-reactivity with other enterotoxins. Artificially contaminated milk with different concentrations of rSEAGepis, SEA, and SEG was detected by the established ic-ELISA; the recoveries of rSEAGepis, SEA, and SEG were 91.1 to 157.5%, 90.3 to 134.5%, and 89.1 to 117.5%, respectively, with a coefficient of variation below 12%. These results demonstrated that the newly established ic-ELISA possessed high sensitivity, specificity, stability, and accuracy and could potentially be a useful analytical method for synchronous detection of SEA and SEG in milk.

Increasing frequency stability and accuracy in methane e-component lasers

1991 ◽  
Vol 34 (6) ◽  
pp. 581-584
Author(s):  
A. N. Titov ◽  
Yu. G. Rastorguev
Keyword(s):  
Frequency Stability ◽  
Stability And Accuracy

scholarly journals Computer Modeling of Second-Order Recursive Digital Filters of the Automated Design Signaling System

2017 ◽  
Vol 18 (4) ◽  
pp. 484-486
Author(s):  
S. P. Novosyadly ◽  
R. V. Valter
Keyword(s):  
Computer Modeling ◽  
Analytical Method ◽  
Digital Filters ◽  
Automated Design ◽  
Second Order ◽  
Signaling System ◽  
Modeling Software ◽  
Single Radius ◽  
Recursive Digital Filters

In the article the analytical method of modeling software recursive digital filters of the second order with zeros on the circle of the single radius is presented. The corresponding algorithm of scaling of this composition of filters for signal CAD is developed.

scholarly journals Influence of Mechanical, Thermal, and Electrical Perturbations on the Dielectric Behaviour of Guest-Encapsulated HKUST-1 Crystals

2020 ◽  
Author(s):  
Arun Babal ◽  
Jin-Chong Tan
Keyword(s):  
Dielectric Response ◽  
High Sensitivity ◽  
Dielectric Materials ◽  
Mechanical Stimuli ◽  
Operational Parameters ◽  
Materials Synthesis ◽  
Guest Molecules ◽  
A Value ◽  
Metal Organic ◽  
Chemical Selectivity

<p>Metal-organic frameworks (MOFs) are the emerging low-<i>k</i> dielectric materials for application in next-generation microelectronics and telecommunication devices. MOF dielectrics can function as smart sensors with high sensitivity and chemical selectivity, by leveraging the ubiquituous dielectric response of MOFs and overcoming the limitations of DC conductivity and fluorescence approaches. Herein we study the effects of materials synthesis, applied mechanical stress (37-520 MPa), varying temperature (20-100°C), and guest encapsulation on the frequency-dependent dielectric response (4 Hz to 1 MHz) and AC conductivity of the HKUST-1 MOF. Particularly, we show that the confinement of the triethylamine (NEt<sub>3</sub>) guest molecules in HKUST-1 (host) yields the NEt<sub>3</sub>@HKUST-1 system that is tuneable <i>via</i> mechanical, thermal and electrical perturbations. Within the frequency range of 10 kHz to 1 MHz, at 20 °C we show that the dielectric constant (𝜀‘) of the guest-encapsulated system could be tuned to attain a value of between 2.8 and 7.2; at 100 °C, an even greater range of 𝜀‘ from 3.1 to 9.5 could be achieved. Conversely, we found the dielectric tuneability of the porous (guest-free) HKUST-1 is relatively more limited (𝜀‘ = 2.8 to 4.9) whist employing the same operational parameters. Furthermore, the confinement of guest molecules in HKUST-1 enhances the mechanical resilience and yield strength of the powders subject to a compressive pelleting stress. Together, the results elucidate the new potential for exploiting host-guest interactions in MOFs, coupled with electro-thermo-mechanical stimuli to regulate the precise dielectric response of a designer low-<i>k</i> material.</p>

MATHEMATICAL AND COMPUTER MODELING OF HETEROGENEOUS RESOURCES PLANNING AND ALLOCATION IN INDUSTRIAL NETWORKS

2021 ◽  
Vol 77 ◽  
pp. 68-80
Author(s):  
D. A. Perepelkin ◽  
◽  
A. M. Pham ◽  
Keyword(s):  
Mathematical Modeling ◽  
Computer Modeling ◽  
Linear Functional ◽  
Functional Dependencies ◽  
Industrial Networks ◽  
Gert Networks ◽  
Distribution Laws ◽  
Gert Network ◽  
Resources Planning ◽  
Heterogeneous Resources

The aim of the work is to develop mathematical and software tools for modeling planning and allocating processes of heterogeneous resources in industrial networks. Two approaches to the application of functional dependencies of random values of resources to the model of GERT-network are proposed: parallel and sequential, which corresponds to the processes of planning and allocating resources. The approaches proposed in the work allow expanding the capabilities of classical GERT-networks. To generalize the process of implementation and automation of calculations, a computer modeling system has been developed. The main stages of mathematical modeling of industrial networks based on GERT-models are also proposed. An algorithm for planning and allocating of heterogeneous resources in t industrial networks has been developed. A computer modeling system ResourceModeler has been developed, which allows calculating the distribution laws of output values in a GERT-network using linear functional dependencies based on the heterogeneity of resources.

scholarly journals Influence of Mechanical, Thermal, and Electrical Perturbations on the Dielectric Behaviour of Guest-Encapsulated HKUST-1 Crystals

2020 ◽  
Author(s):  
Arun Babal ◽  
Jin-Chong Tan
Keyword(s):  
Dielectric Response ◽  
High Sensitivity ◽  
Dielectric Materials ◽  
Mechanical Stimuli ◽  
Operational Parameters ◽  
Materials Synthesis ◽  
Guest Molecules ◽  
A Value ◽  
Metal Organic ◽  
Chemical Selectivity

<p>Metal-organic frameworks (MOFs) are the emerging low-<i>k</i> dielectric materials for application in next-generation microelectronics and telecommunication devices. MOF dielectrics can function as smart sensors with high sensitivity and chemical selectivity, by leveraging the ubiquituous dielectric response of MOFs and overcoming the limitations of DC conductivity and fluorescence approaches. Herein we study the effects of materials synthesis, applied mechanical stress (37-520 MPa), varying temperature (20-100°C), and guest encapsulation on the frequency-dependent dielectric response (4 Hz to 1 MHz) and AC conductivity of the HKUST-1 MOF. Particularly, we show that the confinement of the triethylamine (NEt<sub>3</sub>) guest molecules in HKUST-1 (host) yields the NEt<sub>3</sub>@HKUST-1 system that is tuneable <i>via</i> mechanical, thermal and electrical perturbations. Within the frequency range of 10 kHz to 1 MHz, at 20 °C we show that the dielectric constant (𝜀‘) of the guest-encapsulated system could be tuned to attain a value of between 2.8 and 7.2; at 100 °C, an even greater range of 𝜀‘ from 3.1 to 9.5 could be achieved. Conversely, we found the dielectric tuneability of the porous (guest-free) HKUST-1 is relatively more limited (𝜀‘ = 2.8 to 4.9) whist employing the same operational parameters. Furthermore, the confinement of guest molecules in HKUST-1 enhances the mechanical resilience and yield strength of the powders subject to a compressive pelleting stress. Together, the results elucidate the new potential for exploiting host-guest interactions in MOFs, coupled with electro-thermo-mechanical stimuli to regulate the precise dielectric response of a designer low-<i>k</i> material.</p>

scholarly journals Boosting SARS-CoV-2 qRT-PCR detection combining pool sample strategy and mathematical modeling

2020 ◽  
Author(s):  
Isadora Alonso Correa ◽  
Tamires de Souza Rodrigues ◽  
Alex Queiroz ◽  
Leon de Franca Nascimento ◽  
Thiago Wolff ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Statistical Modeling ◽  
In Silico ◽  
Cost Savings ◽  
In Silico Analysis ◽  
Standard Technique ◽  
High Sensitivity ◽  
Molecular Testing ◽  
Testing Program ◽  
Qrt Pcr

qRT-PCR is the gold standard technique available for SARS-CoV-2 detection. However, the long test run time and costs associated with this type of molecular testing are a challenge in the actual pandemic scenario. Due to high testing demand, pooling sample strategy is an interesting approach to allow cost savings. We aim to evaluate pooling tests in experimental procedures, as well as perform in silico statistical modeling analysis validated with specimen samples obtained from a mass testing program of Industry Federation of the State of Rio de Janeiro (Brazil). Although the sensitivity reduction in samples pooled with 32 individuals was observed, the high-test sensitivity is maintained even when 16 and 8 samples were pooled. The in silico analysis showed high-cost savings in populations with positive rates lower than 15.0% according to the pool size. This data was validated with the results obtained in our mass testing program: statistical modeling predicted a cost saving of 48.0%, which in practice, was 51.5%, already considering the expenditures with pool sampling that were analyzed individually. Our data confirmed that mathematical modeling is a powerful strategy to improve the pooling approach for SARS-CoV-2 mass testing around the world while maintaining high sensitivity and robustness.

scholarly journals A Comprehensive Analysis of the Determinants of Swap Problem in the Supply Chain of the Petroleum Industry

2016 ◽  
Vol 5 (6) ◽  
pp. 108 ◽  
Author(s):  
Raed Al-Hussain ◽  
Reza Khorramshahgol
Keyword(s):  
Mathematical Modeling ◽  
Supply Chain ◽  
Petroleum Industry ◽  
Cost Savings ◽  
Comprehensive Analysis ◽  
Decision Makers ◽  
Operational Parameters ◽  
Supply Chain Costs ◽  
The Cost

Applying mathematical modeling to solve swap problems, specifically in the petroleum industry, have proven to help the decision makers to better determine what, where, and how much to swap in order to reduce supply chain (SC) costs and improve its surplus. However, for a better determination of the alternatives and a more profound evaluation of the tradeoffs among them, a comprehensive analysis of the results and a thorough investigation of their impact on the parties involved in swap are crucial. This research performs a detailed sensitivity analysis of the swap problem to examine the effect of different operational parameters on the cost savings realized along the supply chain of the organizations involved in swap. Findings of this study suggest that, if performed properly, swap can significantly reduce supply chain costs and may result in substantial savings, creating a win-win situation for all parties engaged in swap.

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