model estimation
Recently Published Documents


TOTAL DOCUMENTS

1041
(FIVE YEARS 226)

H-INDEX

43
(FIVE YEARS 5)

Author(s):  
Jose Alfredo Palacio-Fernádez ◽  
Edwin García Quintero

<span>This article determines the internal parameters of a battery analyzed from its circuit equivalent, reviewing important information that can help to identify the battery’s state of charge (SOC) and its state of health (SOH). Although models that allow the dynamics of different types of batteries to be identified have been developed, few have defined the lead-acid battery model from the analysis of a filtered signal by applying a Kalman filter, particularly taking into account the measurement of noise not just at signal output but also at its input (this is a novelty raised from the experimental). This study proposes a model for lead-acid batteries using tools such as MATLAB<sup>®</sup> and Simulink<sup>®</sup>. First, a method of filtering the input and output signal is presented, and then a method for identifying parameters from 29 charge states is used for a lead-acid battery. Different SOCs are related to different values of open circuit voltage (OCV). Ultimately, improvements in model estimation are shown using a filter that considers system and sensor noise since the modeled and filtered signal is closer to the original signal than the unfiltered modeled signal.</span>


Author(s):  
Ash Bullement ◽  
Benjamin Kearns

AbstractSurvival extrapolation plays a key role within cost effectiveness analysis and is often subject to substantial uncertainty. Use of external data to improve extrapolations has been identified as a key research priority. We present findings from a pilot study using data from the COU-AA-301 trial of abiraterone acetate for metastatic castration-resistant prostate cancer, to explore how external trial data may be incorporated into survival extrapolations. External trial data were identified via a targeted search of technology assessment reports. Four methods using external data were compared to simple parametric models (SPMs): informal reference to external data to select appropriate SPMs, piecewise models with, and without, hazard ratio adjustment, and Bayesian models fitted with a prior on the shape parameter(s). Survival and hazard plots were compared, and summary metrics (point estimate accuracy and restricted mean survival time) were calculated. Without consideration of external data, several SPMs may have been selected as the ‘best-fitting’ model. The range of survival probability estimates was generally reduced when external data were included in model estimation, and external hazard plots aided model selection. Different methods yielded varied results, even with the same data source, highlighting potential issues when integrating external trial data within model estimation. By using external trial data, the most (in)appropriate models may be more easily identified. However, benefits of using external data are contingent upon their applicability to the research question, and the choice of method can have a large impact on extrapolations.


2022 ◽  
pp. 245513332110697
Author(s):  
Abul Kalam Azad

This study aims to investigate the factors that influence household behaviour in cultivating the diversified crops on their cultivable land in Bangladesh. Cragg’s alternative tobit model has been applied to a unique rural household level dataset to find the catalysts of crop diversification. The results obtained portrayed a mixed impression of crop diversification in the country. The estimated results have revealed that the male head of household, the accessibility of information, a greater number of farming parcels and the availability of hired labour seem to govern the decision of a farming household to participate in non-rice crop production, while factors such as the total amount of land, agricultural extension service and irrigation facilities influence rice cultivation. Moreover, the findings obtained from the same Cragg’s alternative tobit model estimation for the Aman, Boro and Aus seasons have also revealed a similar depiction of crop diversification in Bangladesh.


2021 ◽  
Vol 14 (2) ◽  
pp. 206-215
Author(s):  
Tiani Wahyu Utami ◽  
Aisyah Lahdji

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which was recently discovered. Coronavirus disease is now a pandemic that occurs in many countries in the world, one of which is Indonesia. One of the cities in Indonesia that has found many COVID cases is Semarang city, located in Central Java. Data on cases of COVID patients in Semarang City which are measured daily do not form a certain distribution pattern. We can build a model with a flexible statistical approach without any assumptions that must be used, namely the nonparametric regression. The nonparametric regression in this research using Local Polynomial Kernel approach. Determination of the polynomial order and optimal bandwidth in Local Polynomial Kernel Regression modeling use the GCV (Generalized Cross Validation) method. The data used this research are data on the number of COVID patients daily cases in Semarang, Indonesia. Based on the results of the application of the COVID patient daily cases in Semarang City, the optimal bandwidth value is 0.86 and the polynomial order is 4 with the minimum GCV is 3179.568 so that the model estimation results the MSE is 2922.22 and the determination coefficient is 97%. The estimation results show the highest number of Corona in the Semarang City at the beginning of July 2020. After the corona case increased in July, while the corona case in August decreased.


Author(s):  
E.N. Voskresenskaya ◽  
◽  
O.V. Marchukova ◽  
V.V. Afanasyeva ◽  
◽  
...  

The quality of SST anomalies revealed in the equatorial Pacific associated with El Niño (EN) and La Ni-ña (LN) in the CMIP6 project models (KIOST-ESM, MIROC-ES2L and INM-CM4-8) was evaluated by comparing with real events in the period 1950 to 2014 using the ERSSTv5 data sets. It is shown that the ensemble model estimation of the number, intensity and duration of EN and LN corresponds quite well to real conditions. On this basis, the corresponding model ensemble calculations of their future possible changes in 2021-2085 relative to the historical 1950-2014 period were carried out for two possible sce-narios: business-as-usual (SSP2-4.5) and negative (SSP5-8.5).


2021 ◽  
Vol 1 (2) ◽  
pp. 35-39
Author(s):  
Dragan Stankovski

The biggest challenge of delivering projects on time, especially in the field of Telecommunication, is proper planning and correct estimation of the effort. Such estimations while different phases of the development could be extremely thorny and easily can jeopardize final goals and handover on time. Thus, in this paper, the proposed approach of Hybrid model estimation is to reduce such unlike stakes and give a clear definition of “how needs to be done” with regular estimations transferred to Story Points.


Sign in / Sign up

Export Citation Format

Share Document