scholarly journals Measurement of the effect of chromaticity and intensity on colour representation parameters of a CRT display

2015 ◽  
Vol 2 (1-2.) ◽  
Author(s):  
Klára Wenzel ◽  
Ágnes Urbin
Keyword(s):  
Mathematical Model ◽  
The Difference ◽  
The Mathematical Model

The aim of the measurement detailed in this paper was to measure the just-noticable stimuli of the participating subjects. The stimuli were defined by chromaticity and intensity as the main parameters of the mathematical model. The results show correlance between intensity and the just-noticable stimuli, as described in the Weber-Frechner Law but a contradiction was shown after the analysis in the function of chromaticity. This contradiction can be explained by the difference between the sensitivity of the three cones of the eye.

Condition Monitoring Technology for Connecting Part and Sliding Part of Reciprocating Compressor

2017 ◽  
Author(s):  
Yoshifumi Mori ◽  
Takashi Saito ◽  
Yu Mizobe
Keyword(s):  
Mathematical Model ◽  
Natural Frequencies ◽  
Error Function ◽  
Connecting Rod ◽  
Value Analysis ◽  
Before And After ◽  
The Difference ◽  
Bending Modes ◽  
Parameter Values ◽  
The Mathematical Model

We focused on vibration characteristics of reciprocating compressors and constructed the mathematical model to calculate the natural frequencies and modes for crank angles and proposed a method to estimate the degree and the suspicious portion of failure by difference of temporal parameter values obtained using measuring data in operation and the mathematical model. In this paper, according to the proposed method, a case study is carried out using the field data, where the data were acquired before and after the failures occurred in the connecting parts of connecting rod, to prospect the difference between each parameter value for two operating states. Inspecting resonant characteristics each in the frequency response data relating to the natural frequencies for bending modes of the piston rod, we determined two resonant frequencies, which could correspond to the 1st and 2nd mode about bending of the piston rod. To equate the calculated each natural frequency from eigen value analysis based on the proposed model with each resonant frequency, we define the error function for the identified problem, namely optimum problem. In the identified results, it is found that some parameter values have much difference and the corresponding failure could occur around the connecting rod. We could show the possibility to detect both the change of the parameter values and the deterioration parts for two different kinds of the operating states by our proposed method.

Updating the Mathematical Model of a Structure Using Vibration Data

2005 ◽  
Vol 11 (12) ◽  
pp. 1469-1486 ◽  
Author(s):  
Ashutosh Bagchi
Keyword(s):  
Mathematical Model ◽  
Model Updating ◽  
Three Dimensional ◽  
Field Tests ◽  
Mode Shapes ◽  
Actual Structure ◽  
Shell Elements ◽  
Vibration Data ◽  
The Difference ◽  
The Mathematical Model

Model updating is an important step for correlating the mathematical model of a structure to the real one. There are a variety of techniques available for model updating using dynamic and static measurements of the structure’s behavior. This paper concentrates on the model updating techniques using the natural frequencies or frequencies and mode shapes of a structure. An iterative technique is developed based on the matrix update method. The method hasbeenappliedtothefiniteelement models of a three span continuous steel free deck bridge located in western Canada. The finite element models of the bridge have been constructed using three-dimensional beam and facet shell elements and the models have been updated using the measured frequencies. From the study it is clear that the initial model needs to be built such that it represents the actual structure as closely as possible. The results demonstrate that the difference between the modal parameters from the model and field tests affect the quality of the model updating process.

An optimized mathematical model for cancer patient care planning in the COVID-19 era.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e18663-e18663
Author(s):  
Isabel Blancas ◽  
David Martínez-Rodríguez ◽  
Fernando Rodríguez-Serrano ◽  
Rafael Jacinto Villanueva ◽  
Jose Manuel Garrido
Keyword(s):  
Mathematical Model ◽  
Demographic Data ◽  
Real Data ◽  
Oncologic Surgery ◽  
Number Of Patients ◽  
Oncologic Patients ◽  
Hospital Resources ◽  
The Difference ◽  
Using Data ◽  
The Mathematical Model

e18663 Background: The COVID-19 pandemic has threatened to collapse hospital and Intensive Care Unit (ICU) services, and it seems to limit the care of oncologic patients. The objective was to develop a mathematical model designed to predict the hospitalization and ICU admission demands due to COVID-19 to forecast the availability of hospital resources for the scheduling of oncological surgery and medical treatment that require hospitalitation or possible use of ICU services. Methods: We have implemented a SEIR model designed to predict the number of patients requiring hospitalization and ICU admissions for COVID-19. We evaluated the model using the number of cases registered in the hospitals of the province of Granada (Spain), that altogether cover 914,678 inhabitants. Calibration was performed using data recorded between March 15 and September 22, 2020. After that, the model was validated by comparing the predictions with data registered between September 23 and November 7, 2020. Besides, we performed a predictive analysis of scenarios regarding different possible sanitary measures. Results: Using patient registered data we developed a mathematical model that reflects the flow among the different sub-groups related to COVID-19 pandemics (Table). The best algorithm that fitted the disease dynamics was Particle Swarm Optimization, that minimized the difference between model output and real data used to calibrate the model. The validation phase showed the accuracy of the predictions, especially concerning trends in hospitalizations and ICU admissions. The different scenarios modelled on November 10, 2020 allowed us to predict the evolution of the pandemic until July 1, 2021, and to detect the peaks and valleys of disease prevalence. Conclusions: The mathematical model presented provides predictions on the evolution of COVID-19, the prevalence and hospital or ICU care demands. The predictions can be used to detect periods of greater availability of hospital resources that make it possible to schedule the oncologic surgery and intensify the care for oncologic patients. Furthermore, our model can be adapted to other population by recalibrating the model according to demographic data, the local evolution of the pandemic and the health policies. [Table: see text]

scholarly journals Building a mathematical model for the free groundwater Resources of the plain area in the lattakia basin: بناء نموذج رياضي لموارد المياه الجوفية الحرة للمنطقة السهلية في حوض اللاذقية

2021 ◽  
Vol 5 (3) ◽  
pp. 52-37
Author(s):  
Nedaa Saedallah Rajab, Ahmed Mohammed, Sharif Hayek Nedaa Saedallah Rajab, Ahmed Mohammed, Sharif Hayek
Keyword(s):  
Mathematical Model ◽  
Water Resources ◽  
Groundwater Resources ◽  
Water Layer ◽  
Research Area ◽  
Plain Area ◽  
The Difference ◽  
Underground Flow ◽  
The Mathematical Model ◽  
Hydrogeological System

The results of the stratigraphic modeling of the study area showed that the stratigraphic formations constitute a hydrogeological system that is hydrodynamically linked to each other represented by a water layer with a free underground flow.                                                    The results of the mathematical model that was built for the region also showed that the high values of the leaching factor were concentrated in the northern and central part of the research area, where the faults were located, the difference between the input values and the calibration results in most areas of the hydraulic conductivity distribution of the layer did not exceed 10%. The water resources in the northeastern part of the study area are of good quality, large quantities, and easy to invest, with a total intake of (134607.3) m3/day. The thickness of the carrier ranged about 50 m in the northern section and increased towards the area of the falcon band within the course of the Arab River to reach about 125 m. As for the thickness of the carrier in the southern section, it ranged between (75 – 60) m. the groundwater system in the study area is stable, and the largest part of the amount of water resources formed in the region to the lateral inflow of the ground and and amounted to about 90% of total value of the resources.

scholarly journals Evaluating the different control policies for COVID-19 between mainland China and European countries by a mathematical model in the confirmed cases

2020 ◽  
Author(s):  
Feng Lin ◽  
Yi Huang ◽  
Huifang Zhang ◽  
Xu He ◽  
Yonghua Yin ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Mainland China ◽  
European Countries ◽  
Control Policies ◽  
Republic Of China ◽  
Rapid Spread ◽  
Control And Prevention ◽  
The Difference ◽  
The Mathematical Model

AbstractThis study focuses on evaluating the different policies of controlling the outbreak of COVID-19 in mainland China and in some European countries. The study is based on mathematical model which is a modified susceptible-infected-recovered (SIR) model. The model takes death and recovery into consideration which in convenience is called the susceptible-infected-recovered-death (SIRD) model. The criterion for the recovered patients is assumed by COVID-19 nucleic acid testing negative. The mathematical model is constructed by retrospective study. Determination of the parameters in the model is based on the epidemic bulletin supplied by the Chinese Center for Disease Control and Prevention (CDC) and National Health Commission of the People’s Republic of China (NHC) from Jan 16 2020 to Mar 5 2020. The data cover the date when the epidemic situation is reported and the data showed that the epidemic situation is almost under control in China. The mathematical model mainly simulates the active cases and the deaths during the outbreak of COVID-19. Then apply the mathematical model to simulate the epidemic situations in Italy and Spain, which are suffering the outbreak of COVID-19 in Europe. The determination of the parameters for the 2 European countries is based on the data supplied by Worldometers. By comparing the difference of the parameters based on the same mathematical model, it is possible to evaluate the different policies in different countries. It turns out that the relatively easing control policies might lead to rapid spread of the disease.

scholarly journals A new approach to the mathematical model of thermal energy balance

2019 ◽  
Vol 97 ◽  
pp. 01028
Author(s):  
Elena Kitaytseva
Keyword(s):  
Mathematical Model ◽  
Thermal Energy ◽  
Heat Energy ◽  
Hot Water ◽  
New Approach ◽  
Hot Water Supply ◽  
The Difference ◽  
The Cost ◽  
The Mathematical Model ◽  
Weight Coefficients

Formation of balance of thermal energy and the heat carrier for a thermal network is carried out for the purpose of increase of efficiency of work of the heat supplying organization. The standard approach proposes to write off the difference between the released and realized heat energy for heat losses. The article proposes a new approach to the formation of the balance of thermal energy and coolant. It includes statistical analysis of telemetry data relating to the released thermal energy. Heat consumption was estimated by contractual load for heating, ventilation and hot water supply. In the mathematical model of the thermal balance for each term weight coefficients were introduced. To obtain the numerical values of these coefficients, the method of least squares was used. The results of checking the adequacy of mathematical models that take into account or neglect thermal losses are presented. The obtained coefficients for the mathematical model of heat balance were used for the mathematical model of mass balance. The results can be used to predict the cost of production and transmission of heat energy and coolant, to assess the efficiency of the heat network and the formation of tariff applications for the future.

scholarly journals A New Mathematical Model for Food Thermal Process Prediction

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Dario Friso
Keyword(s):  
Mathematical Model ◽  
Thermal Process ◽  
Absolute Error ◽  
Process Time ◽  
Heating Process ◽  
Canned Food ◽  
Heat Penetration ◽  
The Difference ◽  
Input Variables ◽  
The Mathematical Model

A mathematical model was developed to correlate the four heat penetration parameters of 57 Stumbo’s tables (18,513 datasets) in canned food:g(the difference between the retort and the coldest point temperatures in the canned food at the end of the heating process),fh/U(the ratio of the heating rate index to the sterilizing value),z(the temperature change required for the thermal destruction curve to traverse one log cycle), andJcc, (the cooling lag factor). The quantitiesg,z, andJcc, are input variables for predictingfh/U, whilez,Jccandfh/Uare input variables for predicting the value ofg, which is necessary to calculate the heating process timeB, at constant retort temperature, using Ball’s formula. The process time calculated using thegvalue obtained from the mathematical model closely followed the time calculated from the tabulatedgvalues (root mean square of absolute errors RMS = 0.567 min, average absolute error = 0.421 min with a standard deviation SD = 0.380 min). Because the mathematical model can be used to predict the intermediate values of any combination of inputs, avoiding the storage requirements and the interpolation of 57 Stumbo’s tables, it allows a quick and easy automation of thermal process calculations and to perform these calculations using a spreadsheet.

RATIONAL DISPOSAL OF PET CONTAINING WASTE AND PROSPECTS FOR THE SYNTHESIS OF NEW POLYMERS

2021 ◽  
pp. 12-20
Keyword(s):  
Mathematical Model ◽  
Ethylene Glycol ◽  
Polyethylene Terephthalate ◽  
Diethylene Glycol ◽  
Household Waste ◽  
Polyester Polyol ◽  
Unsaturated Polyesters ◽  
New Type ◽  
The Difference ◽  
The Mathematical Model

As a result of the research on the utilization of polyethylene terephthalate-containing household waste, a promising direction was identified in the production of a new type of secondary polyethylene terephthalate (SPET) - unsaturated polyesters. It was revealed that the final product, which formed when the alcoholization process is complete in any proportion of of glycol and secondary polyethylene terephthalate, is the bisalkylent terephthalate of terephthalic acid; the content of the alcoholysis product consists of bisalkylent terephthalate, different molecule mass, functionally hydroxyl-containing complex polyester polyol and free diols. The laws of alcoholization of secondary polyethylene terephthalate have been studied and the mechanism has been established. Studies have shown that, in contrast to existing theories, such as the formation of ethylene glycol in the polycondensation of phthalic anhydride bisalkylene glycol derivatives, the increase in ethylene glycol in the process was found to be due to the exchange of diethylene glycol in the macrochain. The formation of unsaturated polyesters goes stage by stage, first ethylene-, diethylene glycol acid esters are formed, then they are exposed to hydroxyl-containing oligomers - secondary polyethylene terephthalate alcohol products. A mathematical model of the process of alcoholization of SPET and diethylene glycol was created, studies showed that the difference between the values obtained as a result of the mathematical model and experiments are less than 5%. The unsaturated polyesters were synthesized on the basis of SPET alcoholization products. Many of them have shown their superiority over unsaturated polyesters PN-1, PN-3, PN-15, which are used in industry for general purposes. By developing unsaturated polyesters on the basis of secondary polyethylene terephthalate alcohol products, it was found that the structure of these polyesters is close to that of imported resins "Body", 196, 196A, used in industry.

scholarly journals 3D AND 1D SIMULATIONS OF DIESEL PARTICULATE FILTER (DPF)

2022 ◽  
Vol 36 (06) ◽  
Author(s):  
NGUYEN MINH PHU ◽  
LE THANH DANH
Keyword(s):  
Mathematical Model ◽  
Open Source Software ◽  
Shooting Method ◽  
Exhaust System ◽  
Momentum Equation ◽  
Particulate Filter ◽  
Ansys Fluent ◽  
Pressure Distributions ◽  
The Difference ◽  
The Mathematical Model

DPF is an important device in the exhaust system of Diesel engine. In this paper we simulate velocity and pressure distributions in DPF to determine kinematic and hydraulic characteristics. This will provide the basis for designing and selecting size of channels in DPF. Numerical simulations were made using ANSYS Fluent commercial software and OpenFOAM open-source software. The results show that the difference between the two softwares is negligible. A compact 1D mathematical model developed based on the Darcy equation, momentum equation and continuity equation. The mathematical model solved by shooting method for boundary value problem. Simulation results from 1D and 3D approaches are very coincident.

scholarly journals Research of the mathematical model of long-lasting armed conflict taking into account hereditarity

2021 ◽  
pp. 48-55
Author(s):  
И.С. Кокорев
Keyword(s):  
Mathematical Model ◽  
Fractional Derivative ◽  
Numerical Solution ◽  
Armed Conflict ◽  
Control Parameters ◽  
Generalized Model ◽  
The Difference ◽  
Lanchester Model ◽  
The Mathematical Model

Рассматривается обобщённая модель длительного вооруженного конфликта в условиях эредитарности. Ставится задача по обобщению классической модели Ланчестера и записывается в разностной подстановке через аппроксимацию дробной производной. Приводятся графики переходных процессов и фазовых траекторий, которые были построены с помощью численного решения в зависимости от различных значений управляющих параметров. A generalized model of a long-term armed conflict in conditions of heredity is considered. The problem is posed to generalize the classical Lanchester model and is written in the difference substitution through the approximation of the fractional derivative. The graphs of transient processes and phase trajectories are given, which were constructed using a numerical solution depending on various values of the control parameters.

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